New system, ~$1000 budget, primarily gaming

This is intended to be a gaming PC/VMware ESX/ESXi lab (and maybe I'll turn it into a hackint0sh, too). I posted an earlier version in April but didn't buy it then. My budget is around $1000, but I'm willing to go over. The version below comes in at $1062.67 CAD according to newegg.ca (with some instant rebates). I'm planning to buy by Sunday.

Motherboard: GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard
CPU: Intel Core 2 Quad Q9550 Yorkfield 2.83GHz 12MB L2 Cache LGA 775 95W Quad-Core Processor - Retail
Memory: G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBNT - Retail
Case: Antec Three Hundred Black Steel ATX Mid Tower Computer Case - Retail
Power supply: Antec EA650 650W Continuous Power ATX12V Ver.2.2 / EPS12V version 2.91 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
GPU: ASUS EAH4890/HTDI/1GD5 Radeon HD 4890 1GB GDDR5 PCI Express 2.0 x16 Video Card - Retail

Some advice on the GPU would be greatly appreciated (and anything else I'm missing). I'm open to the idea of crossfire, although it seems to me that could be a headache. I like first person shooters, although I'm usually more worried about the gameplay than the graphics.

I may overclock, too. I've never actually gotten around to it, though. I'm open to suggestions on the CPU, too (would a dual core be better?), and I'm clueless about CPU coolers these days.

I have a monitor and I'll either use a SATA drive I already have or buy another one. I haven't decided what to do about the OS yet. I'll budget for that separately.

I think for your budget, a good i7 system may be out of reach. They generally run ~$1300 USD. Since the system is primarily for gaming, you'd be better off with the e8500.

Any thoughts of xfire down the road?

I'd like crossfire to be an option down the road, if I could. Not sure I'll actually do it, though.

If I bought a cheaper CPU, what would be an upgrade for the GPU?

I'll look at i7 this weekend. I am *reasonably* sure I can install VMware ESXi on this motherboard, but I'd have to check out the i7 motherboards.

Your build is perfect for what you want to do to be honest,chances are you are never going to use the i7 to it's full potential anyway but it could fit in your budget and offer a great upgrade path and some future proofing however if that's the case you would be better off waiting for the i5...if you went amd the 955 would give great performance and leave you with some extra cash to spend. The 4890 is already powerful enough there is really nothing else besides the gtx 295 and cross fired solutions that can beat it so i think you are fine there both the phenom 2 x4 955 and the i7 offer good performance and a solid upgrade path i would go with the phenom 2 because it is only based on the am 3 socket whereas the i7 is based on the 1336 yet intel is releasing its mainstream chip on a different socket in a few months (basically if you buy the i7 you can only upgrade to 1336 nehalem chips while everyone else will be buying cheaper and well performing i5's) whereas the 955 and all other amd chips will be based on one socket giving you a more diverse and cheaper upgrade path in the future. The lga 775 you posted is nice but at this moment amd would make more sense otherwise wait for intel core i5