Change the motherboard to the ASUS P5B Deluxe
. Whichever Canadian site you're buying from should have it. You'll never use what the 680i has to offer.
Change the optical drive to a DVD burner.
Change the Power Supply to a Forton or Antec 450W or 500W version.
Find the cheapest reliable set of DDR2-800 that you can find and go with that. You aren't going to be stressing the memory with that processor, and any 2 x 1GB set of DDR2-800 will do.
Change the processor to an E6600. You can overclock both processors to the same speeds.