That's a lot like my main machine.
Q6600
ASUS P5B-Deluxe
G. Skill PC6400 4GB 4-4-4-12
EVGA 7900GTO 512 MB
WD 150 SATA RAPTOR Vista 32
WD 74 SATA RAPTOR Windows XP PRO
WD 250 SATA storage
ASUS DVD-ROM
ASUS DVD-RW Lightscribe
Thermaltake 700 watt quad 12v rail PSU
Thermaltake Mozart tower
Thermaltake media Lab Led Remote control
Zalman 9500 Led HSF
Audigy 2 Soundblaster
Boston Acoustics
Pinnacle Studio 9 PCI
Vista Experience rating is 5.9.
So are you going to build it or are you just speculating?