If you cannot find them on any of the Toshiba sites, then you will have to go into the hardware manufactures site ie: Intel, Realtec and find the drivers that way (no easy method unless Toshiba has them on site),
I would suggest doing dual booting ie: adding another partititon and putting XP on that. Leave the Vista where it is until you get XP up and running the way you want it.
If you just go ahead and dump Vista and cant find all the XP drivers and utilities, then you will have nothing.
Another thing you can do, is to scroll thru all the posts on the site for a few pages and see if there are any posts with regards to xp drivers for a P205. The Search function isnt working so you have to scroll.