uhhh, I could suggest switching brands...if that helps
i bought a canon i850 for my xp machines, and use it flawlessly on Vista...I think canon HAS drivers for Vista, and they work. Though not sure you need canon external drivers now, they may be included already.
I say the above because I downloaded canon Vista drivers when I was doing the Vista beta...and can't seem to recall if I installed drivers after Vista Ultimate or if they were already included in the Vista drivers library.
Support - Photo Printer - i850 Series - Canon USA Consumer Products
This model is a few years old, so I think you can find a more updated model to suit your needs.