If I were building a system today, I’d use the
Asus A8N-SLI Deluxe. With good Corsair low latency RAM, it is ready for easy upgrades to a faster CPU, SLI video, and Raid.
The BFG GeForce 6600 and 6800 cards are very good bang for the buck. Get one now to stay in budget, add another later for a super upgrade after the price comes down.
That’s what I would do.