good comments, I like the lexus-toyota analogy. Would the 975 be the LS 600h? Or would that be gulftown?
I agree completely with aigomorla. A 920/860 is all you need. At stock, the performance difference is pretty negligible for the price increase of the next tier, but once OCing, they generally have pretty similar terminal frequencies, depending on the luck of the batch. Any D0 should do 4.2 with a good cooler, at least that is my finding with my chip. Most 860's should max around that or abit above. I have heard of people getting 4.3 on 860, and 4.5 on 920's. This is doable on high end air.
Even if not overclocking, the 860 should be more than fine. No need to nearly double the price for an 870 just for an extra multi or so. Same with the 950.
Seeing as you probably have a relatively larger budget, I would get a good board, a good PSU, and 1-2 5870's.
And as for cars, what do yall think of the new Mercedes E class?