Well I cant see any flaw on your system you have build. Just be aware that the psu you choose has only 1x pci 6 pin and 1x pci 6+2 pin so you will will not be able to add a 2nd gpu since your gpu will take both of the connectors. this is 20$ more but you asked for Xfire (sli for 460gtx ) later so i guess it worth it. Antec High Current Gamer Series 900W ATX Power Supply http://www.microcenter.com/single_product_results.phtml...
I am confused...you said you want to Xfire, but you have a 460 up there... On that subject...why do you wish to SLI/Xfire anyway? I can assure you, a 460 will be good enough for max settings @ 1080p. Are you trying for Bulldozer later, is that why you went with the AM3+? If not, then you can save a lot of money with a different mobo, CPU wise, you can go lower for a gaming rig too. Anyways, I was doing a gaming build for my daughter: it came out to 468 after discounts on NewEgg, which included Win7 Home (which you don't need an OS anyway)
I got a 970 mobo for Bulldzoer and a GTX 460 will definitely NOT be able to run DX11 games like BF3 at max. Therefore, after my GTX 460, I'll crossfire 6950's which WILL be able to run everything at max and a Bulldozer so it isn't bottlenecked by my CPU.
haha i knew you were gonna go for the BD thats why I didnt change it most people will even I will as well it sounds like it will be a great chip. Yes you are gonna want a better GPU like you've already said to play BF3 at max settings 6950's will be great for it.