Water-Cooling Noob here :/

First off Phantek makes amazing cases and are easy to mod. Mod and Watercoling friendly for the whole Enthoo series). Fractal Design is cheaper, but not nearly as good.

If you are just cooling the CPU, honestly I would just get an AIO (All in one) cooler and call it a day. They have come a looooong way since the Corsair H50. So much cheaper and hassle free for about 3 years (than it dyes out or pump dies). Only reason to go full blown water cooling now is if you have a video card and or you just want something that look very cool (when done right).

best cpu block out there period. i recommend this because you can always go and get another rad to throw in the loop, but once you have already gone and spent $60-$80 for a cpu block you best make sure to get a really good one.

https://shop.ekwb.com/water-blocks/cpu-blocks/supremacy-evo?dir=asc&order=price

as for rads, get what you like most 240mm rads will suffice, going more expensive is mostly bling, lots of channels are good, full copper construction is nice, fins per inch should be as dense as reasonable.

do not use an aluminum radiator ever. do not use any aluminum in your loop at all. really you will thank yourself for it later.

also make sure to get some good static pressure fans with very little space between the blades (vs a faster/more cfm fan with thing blades)

pump, make sure its a good one, last thing you want is a pump to die after a month.

always, always run a single metal in your circuit, you can mix copper and nickel sometimes (depends on the nickel), you can mix copper and brass as well. the very last thing you want is galvanic corrosion.

remember even tho barbed fittings aren't the prettiest they really are the most dependable, most quick disconnects and adjustable fittings are just a hazard waiting to happen.

absolute best coolant you can use is straight up distilled de-ionized water with unmixed automotive antifreeze 70% water 30% antifreeze.

water is the best fluid to use because of its thermal properties, the purest water possible keeps contaminants out of the system. automotive antifreeze will kill anything trying to live in your loop, will lubricate your pump and prevent corrosion.

you can go as low as 80% water and 20% coolant for slightly better temps but the 70/30 mix should prevent any corrosion for the lifetime of your loop.

do not use dyes or silver coils, you specifically do not need to use a silver coil if you are running a full copper loop (copper is a biocide).

all dyes over time will break down, clot up, depreciate your cooling performance or otherwise "expire" because of the heating/cooling. some dyes may last years, some weeks but ALL dyes will eventually break down. pure water and automotive antifreeze will only need flushing/refilling every 5 years or so.

I would avoid dye just because it will stain everything and it does not come off. I just been using distilled water over the years with a silver coil to avoid ick from growing.

I've used Barbs and Compression fittings, both are good, barbs sounds like its better but unless you really clamp it down, it can leak. Compression can leak easier I think, but the chances are just as low if you use the right compression for the tube.

For the pump, i've used it all and my worst experiences so far has been the bay pump/rez. I had all 3 crack and leak from the vibrations of normal use. So I just use the pump and rez separate. it sticks out, but no leaking issues.

Lastly the BEST block out currently is the Heatkiller 4 PRO. Its nearly $100 but damn does it cool well.