Also as far as video cards, I'm pretty equal in my opinion on what's best between ATI & Nvidia cards. I've mentioned Radeon HD 7970 first in my recommended card mainly cuz of price point. The top ATI Radeon card's price is about the same as the Nvidia GTX 670. It's also faster than the 670 (comparable to 680). In terms of performance, I'll take as an example the card I'm using (GTX 680). The 680 can max out any current games you throw in it with just a single card. I'm sure the 7970 can max out any current games you throw in it too. I think the 670 can max out as well as the performance gap between the card & that of the 680 is not that much. Unless you're not into stereoscopic 3D gaming, get the ATI card.
I don't recommend for you to buy 2 cards to SLI/Xfire right now if funds are limited. A single card will keep you going as long as you get any of the recommended cards. In the future, if you need to add additional cards use at least 2 of those top cards. There's really no need for you to do tri or quad SLI/Xfire if what you're into is just playing BF3, COD BO2, Crysis 3, etc. You're not aiming for top benchmark number here but mainly using the cards for gaming at max (it hurts seeing the electric bill too even if the 600 series Nvidia cards is not that power hungry than the previous 500 series). It's a waste of money really if you pool your resources into using lots of cards when you can do it to a minimum. I can truly understand for some people to mainly use it as a bragging right having as those high powered cards in their rigs. If I have so much money I'll probably do a quad SLI/Xfire too.
Cevat Yerli's statement about Crysis 3 "will melt your PC" is overblown. He's mainly describing the graphic potential of the game that its going to be better than the previous ones. The CryENGINE 3 game engine used in Crysis 3 though new is not something that's not been used before. The mod SDK version of the game engine was used to create custom maps, mods & contents for Crysis 2. In the Crysis 3 game there's probably some enhancements done but what Mr. Yerli meant is that if you really need to level up your game in Crysis 3 you need to level up your game components too (probably true if you have a mid range set up but if you're using the top ATI/Nvidia cards now you're still very much in the game with Crysis 3).
As far as PSUs, the 600 series cards as I've previously mentioned are not as power hungry. From what I know a good 750 watt PSU can run 2 of those cards on SLI. I recommend for you to get a 850 watt high quality PSU to have some headroom for future overclocking. You can get an Antec, Corsair or Enermax 850 watts PSU. Any of those brands I've used in the past & highly recommended.
Be careful sacrificing getting a much cheaper component to save money. You're creating a quality build here. Current intel from the experts that the next line of Intel core processor (Haswell) will launch 1st half of 2013 (probably April the earliest). If you get your top components now, you'll have a rig that can compete with the big leagues. Even after Haswell comes, you still have a rig that's gonna run fast & will last long.
Give us an update of how much you're spending with those recommended components. I'll recommend probably for you to change your CPU cooler if within the price range.Edited by Cheaptrick - 9/14/12 at 8:04am