+1 to Venom.
If you want to OC, then go with a Duo: E8500/8400. Or if you want to save a little budget, then the E7400 (R0 stepping). Duos OC higher than quads. However, if you've done your homework and determined that you want a quad, then by all means get the Q6700 if you can afford the incremental cost over the Q6600.
You'll need to finalize your platform (LGA 775 or Phenom II), chipset, intended video solution and OS before you can proceed. If LGA 775, then you should decide on Quad vs. Duo.
IMO, you should go for P45 / Duo plus single video card for now. Take the money you save from not using the i7 and put it towards the GPU instead.
As for your selections, a few general comments.
Case: Thermaltake Armor--nice case.
RAM: I would take this
G.Skill Pi Black over your OCZ, although the OCZ has a great price at $35.
Video card: I would go with a newer 55nm Core 216 over the XFX Black. If you decide on a Crossfire mobo, then go with a 4870 1GB card to leave open the option of Crossfire. By your choices on previous posts though, I would guess that you have a preference for nVidia. That being the case, you could probably even fit a GTX 280 into your budget if you'd like, given current prices. However, you might also want to wait for the GTX 285 ($400) on January 15 if that suits your fancy.
HDD: Given some of Seagate's recent problems, switch to the WD Caviar Black drive, with a preference towards the 640GB over the 500GB for a little bit more speed (due to platter density).
OS: If you've decided to go with Vista, then unless you really have a need for Ultimate, Home Premium would suffice, at $100:
here.