Was actually thinking of switching from nVidia to ATI well if i go sli or crossfire i wanted a x38 board instead of a nVidia chipset board havent decided yet though.
Asus Maximus Formula
q6600 (or use that qx6800 you got)
OCZ Reaper 2gb Kit
Add a Case, Optical Drive and HD that you need
Corsair 520hx
Maybe go crazy and add a sound card?