Which of these two systems should I go for?

RazerZ

Judicious
Ambassador
I'd go for something like this:

PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: Intel Core i5-4670K 3.4GHz Quad-Core Processor ($189.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.98 @ OutletPC)
Motherboard: ASRock Z87 Extreme4 ATX LGA1150 Motherboard ($124.99 @ Newegg)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($67.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($57.98 @ OutletPC)
Video Card: MSI GeForce GTX 780 3GB Video Card ($449.99 @ Newegg)
Case: NZXT Phantom 530 (White) ATX Full Tower Case ($115.98 @ Best Buy)
Power Supply: Corsair RM 850W 80+ Gold Certified Fully-Modular ATX Power Supply ($144.99 @ Amazon)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer ($14.99 @ Newegg)
Operating System: Microsoft Windows 7 Home Premium SP1 (OEM) (64-bit) ($89.98 @ OutletPC)
Mouse: Gigabyte GM-M6980X Wired Laser Mouse ($29.99 @ Newegg)
Total: $1316.85
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2014-04-07 19:00 EDT-0400)
 
Both builds are essentially the same, but I would take the PSU from the second build, and use it with the first build, and get some low profile RAM, because the CPU cooler is so big. You should add a 128gb SSD, you can pick one up for about $75. G.Skill Ares series are good. You could go for a cheaper motherboard, but if you want a really high stable OC, a board with a few more OC options will be helpful. Other than that, you have a very solid build.
 


Yes, it will still fit, but if will be taking in air from the back of your video card, so the temps will be higher. If you use low profile ram, you can fin the cooler in the "correct" orientation: taking cool air from the front of your case, and exhausting it out the back.