Asus has a whole bunch of drivers for Vista out. My ASUS mobo sound drivers were available when I installed Vista, but it took me like 3 weeks to find the Windows settings that made them work...
So, you should be able to find ASUS drivers, even for X64.
And yea, everything will run Vista... My Radeon 9800 Pro AGP (With like, 128 megs of videoram and 768 megs of DDR1 333 Ram) ran Aero pretty smoothly. The CPU clock widgit, however, was having a field day jammed up against 100 percent most of the time.