need advice on which windows 7 version?

Hi:

I would like the advices of people in the know of computers and windows, etc. to please tell me for my PC which version of windows 7 (64bit or 32bit) and (home, pro or ultimate) would be the best to take the full advantages of my pc (rams, processor, graphic etc.). Thanks in advance for your reply and a happy new year to all.

MY PC SPEC.:
AMD AThlon II X2 250 (2 cores)(64bit machine) , 3GHZ with 3GB DDR-3 RAM, 650GB Harddrive and Nvidia geforce 9500GS graphic (not integrated).

here is windows experience index for my pc (under win 7 home 64bit)for you to decide which is best: (base score: 5.4)
processor: 6.5
memory 5.9
graphic 5.4
gaming graphic: 6.4
disk data transfer rate: 5.9

P.S. The most important one I need to know which 64 or 32 bit windows.

 

The following is a recent thread discussing which to choose: 32 bit or 64 bit Windows 7.

https://www.wilderssecurity.com/showthread.php?t=266900