you can install linux with this setup, to dual boot with win you have to use the grub boot manager. after linux is successfully installed you manually add these lines to grubs menu.lst:
title Windows XP
root (hd1)
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1
savedefault
boot
this will boot win from your sata raid. the ide with linux must be the first in your boot priority. if you want to be sure that linux doesn't mess up the xp installation you can just disconnect the harddisks during installation.
ps: don't forget the spaces between (hd0) (hd1) and (hd1) (hd0). without it didn't work on my system