How much is this costing? Don't buy a AMD 6 core cpu for gaming. Your paying more for 2 cores that won't even be used for gaming. Buy a i5 2500K or i7 2600K based PC for gaming. Even a AMD X4 is a wiser choice as you can spend the money saved on a better video card.
The motherboard supports CrossFireX, not SLI and definitely not PhysX. And spending money on a video card "dedicated" to PhysX is another bad idea. Buy the single best card you can afford, if you later find that you need more power then buy another identical card for SLI as it will boost overall performance as well as PhysX performance.
Raidmax is one of the worst power supply you can buy, buy a lower wattage power supply from a more reliable manufacturer.
The animated guide to Building a PC. Learn to build a PC from scratch with PCitYourself!
You'll be happier building your own, it just not that hard to do. Post a budget range and I'm sure our members can set you right up