I've never worked with Vista but the biggest problem I got moving XP installs around used to be drivers for the system drive. In your case, that shouldn't be a problem.
Reinstalling in place also used to work decently (some settings were picked up from the existing install and so on). So that might be an option if Vista refuses the new mobo without reinstalling.
But first make sure you can't offload the existing computer on someone else (why waste a good mobo+CPU+RAM and the system building work?) and that you're going buy a mobo with compatible slots for your cards.
Thanks, I plan to sell the mobo+CPU+RAM on ebay once I get the upgrade working.
(I'm upgrading for more gaming performance).
Any other hints, or has anyone else tried this typs of thing?