set up your computer with an additional partition as you were planning on installing XP as a second system. Then down load GAG a freeware boot manager. GAG will be better suited for installing XP with Vista then using the built in windows boot manager
GAG, the Graphical Boot Manager
Now try installing the XP to the second partition using gag. play with what drivers that you can that will work with XP...then find the name/ID of the hardware and put it in a google search as name/ID XP driver files and see what you can find.

Also search through DriverGuide.com (printer drivers, cdrom drivers, modem drivers, sound drivers, mouse drivers, monitor drivers, etc.) - DriverGuide.com
this is a free site but you must register. has a nice tutorial for searching their site in various different ways...

also be sure to check the hardware manufacturer's site for drivers as well.

With GAG installed you can work seperately on finding the xp drivers without having to log in and modify the boot ini files and all that garbage!