I'd go for the ASUS P5K, it is slightly more than 70, but only by a few. It would be a lower budget solution, but it would support more upcoming CPUs. Personally, I would wait until Fall to upgrade, as the C2D lineup will have likely dropped in price by then. My plan is to get a higher priced board, like the P5K Deluxe, and a C2D E6600 or E6700 when they are cheaper.
CPU: Intel C2Q Q6600 @ 3000 MHz
RAM: 2GB DDR2 667MHz
Motherboard: Asus P5K Deluxe
Video card: BFG 8800 GTS OC