which memory for vista enterprise 64-bit?

[boogey]

http://www.techist.com/forums/f75/99-9-these-will-my-new-computer-but-other-1-oh-boy-165250/

The above link is what I've decided on, but I'm still undecided on the memory.

I know my brother can get me a free copy of vista enterprise, not sure which one though, 32-bit or 64-bit. I put 64-bit down because I'm assuming it requires more juice. So which memory wll run it better?

Corsair XMS2 4GB (2 x 2GB)
Newegg.com - CORSAIR XMS2 4GB(2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

Crucial Ballistix Tracer 2GB (2 x 1GB)
Newegg.com - Crucial Ballistix Tracer 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

 

[Akubane]

Newegg.com - G.SKILL 4GB(2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
if you're not goign with the mail in rebate. With mail in go with the xms2 XD just a suggestion though.

its not that 64bit Requires more juice to run, but it will recognize more ram. if i were you i'd prolly just go with 2gb of crucial and vista 32bit.