I'm looking to build a gaming PC for under $1500, and was wondering what the best combination of parts would be. While I think a small form factor case would be cool, I don't have any space constraints, so a full ATX tower would be fine as well. I am hoping to include watercooling, possibly custom, for overclocking and especially if it is a small form factor build. For RAM, I'm assuming that a 4x4 GB setup would work well, considering that it is not much more expensive than 2x4GB, but much more future proof. Also, I'm looking at getting a GTX 670 or AMD 7870, unless anyone has a better idea. Also, I'm looking at an Intel core i5 (Ivy Bridge), unless haswell is released before the PC is built.
Any suggestions would be great!
Side note, I'm looking at the Bitfenix Prodigy (mini-ITX) and the NZXT Vulcan, or on the other end of the scale, a CoolerMaster HAF X.