The proc. will probably be a i7-950 unless sandy bridge really impresses me (lol)
Look at the new reviews and benchmarks on them that just came out, SB is great. You can pick up an i5-2500k + motherboard for less than the $400 you planned on spending on the i7-950. Or, if you're going to actually make use of HT, pick up the i7-2600k with a less expensive motherboard.