Any reccomendations for a case that is great for a custom watercooling loop?

Since choosing a PC case is personal choice, go with the one that you like the most. Hardware wise, case that has flexible rad mounts and big transparent side panel would do the best for mounting and showing off custom loop.

I prefer full-tower ATX cases and that's why i have Corsair 760T v2 case (Skylake build) and Corsair 750D AF Edition case (Haswell build) in use, full specs with pics in my sig.

Corsair 760T V2 (comes in as black or white),
specs, black: https://www.corsair.com/eu/en/Categories/Products/Cases/Graphite-Series%E2%84%A2-760T-Full-Tower-Windowed-Case/p/CC-9011073-WW
specs, white: https://www.corsair.com/eu/en/Categories/Products/Cases/Graphite-Series%E2%84%A2-760T-Arctic-White-Full-Tower-Windowed-Case/p/CC-9011074-WW
video review: https://www.youtube.com/watch?v=fLOt8h8-kNY
pcpp: https://pcpartpicker.com/products/compare/6zyxFT,x3Crxr/
Demciflex filter kit: https://www.demcifilter.com/Corsair-760T-Dust-Filter-Kit
video review of Demciflex filter kit: https://www.youtube.com/watch?v=m3LFD_M8Ev0

Corsair 750D (comes as standard or as AF edition),
specs: https://www.corsair.com/eu/en/Categories/Products/Cases/Obsidian-Series%E2%84%A2-750D-Full-Tower-ATX-Case/p/CC-9011035-WW
specs, AF edition: https://www.corsair.com/eu/en/Categories/Products/Cases/Obsidian-Series%E2%84%A2-750D-Airflow-Edition-Full-Tower-ATX-Case/p/CC-9011078-WW
video review: https://www.youtube.com/watch?v=ZpoQqdeqnTo
diff between 750D and 750D AF edition: https://www.youtube.com/watch?v=vjp6ZdOTBPI
pcpp: https://pcpartpicker.com/products/compare/BKW9TW,Rwhj4D/
Demciflex filter kit: https://www.demcifilter.com/Corsair-Obsidian-750D-Dust-Filter-Kit

What i also considered was Corsair 780T (also comes in as black or white),
specs, black: https://www.corsair.com/eu/en/Categories/Products/Cases/Graphite-Series%E2%84%A2-780T-Full-Tower-PC-Case/p/CC-9011063-WW
specs, white: https://www.corsair.com/eu/en/Categories/Products/Cases/Graphite-Series%E2%84%A2-780T-White-Full-Tower-PC-Case/p/CC-9011059-WW
video review: https://www.youtube.com/watch?v=JIyPeXUfFKE
pcpp: https://pcpartpicker.com/products/compare/sNJwrH,vj4NnQ/
Demciflex filter kit: https://www.demcifilter.com/corsair-graphite-780t-filter-kit

You can also look towards Phanteks cases for equal build quality to Corsair, e.g Enthoo Luxe TG edition (comes as black or gray),
specs: http://www.phanteks.com/Enthoo-Luxe-TemperedGlass.html
video review: https://www.youtube.com/watch?v=1EZ6z8Sgwi0
pcpp: https://pcpartpicker.com/products/compare/78zZxr,Vw8H99/
Demciflex filter kit: https://www.demcifilter.com/Phanteks-Enthoo-Luxe-Dust-Filter-Kit

I suggested a build for a similar theme few days ago (the op in that thread had the option to get a 1080ti for 700. But that won't apply to u I guess. So a founders 1080ti or titan xp is my suggestion since the rgb gpu block is compatible only with the founders cards) :

here is a custom loop suggestion (monitor included) :

PCPartPicker part list / Price breakdown by merchant

CPU: AMD - Ryzen 7 2700X 3.7GHz 8-Core Processor ($328.89 @ OutletPC)
Motherboard: Asus - ROG STRIX X470-F Gaming ATX AM4 Motherboard ($209.99 @ SuperBiiz)
Memory: Team - T-Force Delta RGB 16GB (2 x 8GB) DDR4-3000 Memory ($159.99 @ Newegg Business)
Storage: Crucial - MX500 500GB 2.5" Solid State Drive ($114.99 @ Adorama)
Storage: Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive ($59.79 @ OutletPC)
Video Card: NVIDIA - GeForce GTX 1080 Ti 11GB Founders Edition Video Card ($699.00)
Case: Lian-Li - PC-O11DX ATX Full Tower Case ($129.99 @ Newegg)
Power Supply: SeaSonic - FOCUS Plus Gold 850W 80+ Gold Certified Fully-Modular ATX Power Supply ($99.99 @ Newegg)
Operating System: Microsoft - Windows 10 Home OEM 64-bit ($92.89 @ OutletPC)
Case Fan: Corsair - LL120RGB LED (Three Fans With Lighting Node PRO) 43.2 CFM 120mm Fans ($101.75 @ Amazon)
Case Fan: Corsair - LL120RGB LED (Three Fans With Lighting Node PRO) 43.2 CFM 120mm Fans ($101.75 @ Amazon)
Case Fan: Corsair - LL120RGB LED (Three Fans With Lighting Node PRO) 43.2 CFM 120mm Fans ($101.75 @ Amazon)
Monitor: Acer - Predator Z35P 35.0" 3440x1440 100Hz Monitor ($790.98 @ Amazon)
Other: XSPC EX360 High Performance Radiator (Supports 3 x 120mm Fans) ($66.54 @ Amazon)
Other: NZXT Internal USB Hub ($19.97 @ Amazon)
Other: Thermaltake Pacific Temperature Sensor G 1/4 Digital Display with Alarm CL-W151-CU00BL-A ($39.99 @ Amazon)
Other: Thermaltake Pacific Temperature Sensor G 1/4 Digital Display with Alarm CL-W151-CU00BL-A ($39.99 @ Amazon)
Other: Enermax NEOChanger 300ml RGB LED Reservoir and Pump Kits with Remote Control, Synchronisable RGB lighting via Motherboard, ELC-NC150RGB ($119.99 @ Amazon)
Other: CORSAIR RGB LED Lighting PRO Expansion Kit ($39.99 @ Amazon)
Other: XSPC RX360 Triple-Fan Radiator V3 - Black Combo Pack ($109.95 @ Amazon)
Total: $3428.17
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2018-05-03 11:27 EDT-0400

ROG certified model of the case : https://pcpartpicker.com/product/XjrcCJ/lian-li-pc-o11-wgx-atx-mid-tower-case-pc-o11-wgx
better support in the bottom for push pull rad config imo.

monoblock : https://www.ekwb.com/shop/ek-fb-asus-strix-x470-rgb-monoblock
gpu block : https://www.ekwb.com/shop/ek-fc-geforce-gtx-fe-rgb-nickel

the thick rad would be better if its installed in the bottom(more clearance in the bottom of the case and 1080ti 2ghz oc takes about 350w) push pull config with the rad supplied fans in the bottom. 9 corsair LL120 fans with lightning node pros, led stip and nzxt usb hub for connecting them. 3 for each rad and 3 in the side for intake. keep the bottom rad and side fans as intake and top slim rad as exhaust. 2 temperature sensors, 1 for cpu water read-out and 1 for gpu.

only tubes and fittings are missing from the list. add them as u wish.

the setup is a 100hz ultrawide gaming setup for which the 2700X is more than enough with gysnc. 8 cores for ur cpu intensive games and some for ur background apps.

a little something for ur bottom rad design : https://www.jmmods.com/product-page/tribal-design-120mm-x-360mm-fan-grill

They also do custom rgb gpu black plate. The Strix X470 has 2 rgb headera. U have to use a splitter. U have monoblock, gpu block rgb connections. And if you get the rgb black plate and rgb gpu support bracket, that makes 4. Dunno if the nighting node pro is compatible with the rgb connections.

From the X470 Strix specifications :
Internal I/O Ports
1 x Aura Addressable Strip Header(s)
2 x RGB Header(s)

On the other hand, Strix also has an aura sync rgb header which is compatible with the monoblock. So the gpu block goes to one header and the back plate and gpu support bracket goes to the other header with a splitter.

gpu support bracket : https://www.jmmods.com/product-page/addressable-rgb-gpu-support-bracket

my inspiration for this setup (same case BTW) :



speakers if u wish : https://www.amazon.com/Razer-Nommo-Chroma-Computer-Immersion/dp/B078H1T9YD/ref=sr_1_3?ie=UTF8&qid=1525362789&sr=8-3&keywords=razer+nommo

mouse pad : https://www.amazon.com/CORSAIR-MM800-Polaris-Mouse-High-Performance/dp/B01LZ2SET7/ref=sr_1_1?ie=UTF8&qid=1525362819&sr=8-1&keywords=corsair+rgb+mousepad

monitor/table backlighting :https://www.amazon.com/AMIR-LED-Light-Waterproof-controller/dp/B073NXF8B7/ref=sr_1_10?ie=UTF8&qid=1525362841&sr=8-10&keywords=led+strip

keyboard : https://pcpartpicker.com/product/MYtWGX/corsair-k95-rgb-platinum-wired-gaming-keyboard-ch-9127014-na

mouse : https://pcpartpicker.com/product/ZNPKHx/steelseries-rival-600-wired-optical-mouse-62446

so ur total would come to $4300 - 4500

Lian li pc-011dynamic or fractal design define s