Processor get a Q6600 if you need quad core. E7200(2.5 Ghz stock)- budget dual core. E8400(3.0Ghz stock) - hi end dual core. E8600(3.33 Ghz stock) 'highest' end processor.
Better NOT go nvidia for motherboards especially intel versions.
Nvidia will not make any new chipsets for core i7 (nehalem).
But they have complete Socket 778 range of motherboards.
BAD SIDES: nvidia chipsets eats a lot more watts than intel X38/X48. Intel chipsets do tend to OC more. (Can't remember where but somewhere...)
ATi current line up is excellent. Why not CF them(4800 series) or buy the have "HD 4870X2"(Provided you got the $$$ to buy one). Beats the GTX280 in benchmarks. Or get a HD 4870 1GB ver now (it owns 8800GTS 512MB G92, 9800GTX+) and get another later. Better get a 4870 1 GB not the 512MB ver.
If you don't want CF ask others for a good non-CF board. In my mind its this(both are cheap and not the best Overclocking ble board but can run >400FSB, NOT SURE MORE THAN 400 BUT THIS THING SUPPORTS 400)
ga-ep35-ds3(not sold in newegg) (this one has better sound, 6 Phase CPU)
ga-ep35-ds3L(sold in newegg)(this one has cheaper sound, 4 phase CPU: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
GET A WESTERN DIGITAL 640 GB for hard disk. If you need 1 TB. get 2 of this it will make 1.28 TB. Don't get a smaller or bigger hard disk.