SW2009 Computer Upgrade

Hi there I have had SW2009 for awhile, but I want it to run a little better, and create a better computer for it. So I have been researching parts to build a new computer within my means. The problem is that the 2009 edition from what I remember came with two disks, the 32bit, and 64bit versions. Since the computer I was running SW at the time was a 32 bit, I used that one. And I lost the 64bit disk. So does this mean I am stuck useing a 32bit system? Or can I upgrade to a 64bit? Below are the parts I have been thinking of useing:

Phenom 2 X4 840 AMD processsor---Says it supports 32bit applications

Biostar A780L3G mATX Motherboard

Nvidia Quadro FX Video Card

2 x 4gig memory

Windows XP OS

SolidworksGeneral