Just make sure that you have 64-bit drivers available in case something doesn't work. The OS should have a lot of default drivers to use.
The advantage of 64-bit would double the amount of data a CPU can process per clock. You would note a performance increase because a 64-bit CPU can handle more memory and larger files. Unfortunately, most benefits of a 64-bit CPU will go unnoticed without a 64-bit operating system and 64-bit software and drivers which are able to take advantage of 64-bit processor features. HOwever, for the average home computer user, 32-bits is more than adequate for now.
