Help for new computer with matrox rt.x2!

Hey everyone,

I edit weddings and other various events profesionally, and i need to build a computer which fits my needs.So,i have just bought "matrox rt.x2" and i would need some advice to create a new computer.

what i am currently thinking is:

Windows 7, 64bit
SSD intel postville 80gb to install adobe premiere cs4 and windows
intel core i7 930 (i'm thinking also amd phenom 1055T)
P6T Deluxe V2 (Motherboard)
ASUS GTX 285 SVGA or ASUS NVIDIA Geforce GTX 280 or Sapphire VaporX Radeon HD4970 or NVIDIA Quadro FX4600(Graphics card)
Corsair DDR3 3x2GB (RAM)

Is my VGA or my CPU more important, if what i am after, is faster rendering and exporting?

Also, as far as m2v files go, is it better to use adobe encoder, or canopus procoder (again, i am looking for the fastest results)

i can't wait for your suggestions!

you believe that my computer contains the appropriate features for cs5?thank you for your response!

I visited this site

http://blog.krama.tv/list-of-supported-cuda-cards-in-adobe-premiere-cs5/

and i'm wondering if nvidia geforce gtx285 is the same card with ASUS geforce gtx285?

do you have any idea?

thank you!!!