Vic,
I'll give you as many details as I can if it proves necessary. The easiest answer is that if it works well with Vista, it'll work just as well with Windows 7. Tests I've seen for the Win 7 beta show it is more responsive than Vista and will run well on good XP hardware.
I'd just go with an E8500. Q6600 or Q9550 CPU, a Gigabyte P45 chipset mobo, and a video card that suits your gaming needs. The Radeon 3850 and 4850 cards are excellent values based on price/performance.
I'm afraid I haven't installed Win 7 yet. I need a new PC myself with more horsepower and much larger hard disks.