The CPU link is the same link as the case.
Go with an Intel Core 2 Duo (fastest chips at the moment)
Go with this: E6600
based on which fits your budget.
Then go with this motherboard: ASUS P5B-E
Or this motherboard but it doesn't have Firewire ports: Gigabyte DS3
I'd personally go with the DS3 because of its overclocking ability if you don't need the firewire port
Then go with this video card: eVGA 7900GTO
But persoanlly I would get this eVGA 7900GS
until DX10 comes out. At $165 after rebate, nothing comes close as far as performance/price ratio. The 7900GS will play all current games until DX10 comes out
All the parts you picked are very high end, so go with the parts I listed and you'll be good to go