Which version of the system to choose?

Question

Windows

I have a computer (generally average):

• Intel Core 2 Duo 6400 2.12GHz
  
• 4GB DDR2
  
• embedded 384 MB video
  

Now it is used only for work and Linux is installed on it. But there was a need to have Windows for games nearby (in particular, the X-Plane 9 version of the simulator). Yes, it is also available for the penguin, but there are no drivers for the penguin. I opted for Windows XP, because. it is lighter than subsequent versions, there are drivers, and X-Plane has already worked successfully on it.
The question is: is it worth installing 64-bit XP SP2, or is it still the usual 32-bit XP SP3? And will there be a significant difference in the speed of 32 and 64 bit systems?
Thanks in advance.