Sony VAIO VGN-Z690 driver help.

I just got the VGN-Z690 customizable Z series VAIO. I want to put in Vista Ultimate 32-bit to get a fresh start but unfortunately they don't offer it for my version of Vista. They have and "only compatible" with are XP, Business 32-bit, Home Premium 64-bit and Ultimate 64-bit. Their tech support, which is as always lacking, told me they don't have any drives or software utilities for Ultimate 32-bit. I thought that drivers and utilities are categorize in either 32-bit or 64-bit and Vista and XP versions. I didn't know that Vista made it more complicated with pre-built system to have different drivers for each of the versions of the same OS. I don't know if Sony is the only one doing this or the tech support from them just don't know. Maybe it's just me. If I do go on and install my version of Vista, would I be able to use the Business drivers and utilities as it's a 32-bit version? Any other help would really appreciate it. By the way, is their an application that will let me know what drivers I need in my computer?