I do not agree with a Q6600 CPU. You should go with this new 45nm CPU from Intel.
E8400. I would go with a P35 chipset if you want to run one GPU.
P35 from Gigabyte.
4 gigs of ram wont hurt.
The 8800GT looks good.
I don't know if Ultra PSUs are of good quality. If so, the case/psu combo looks fine.
sata HDD is what you want.