I recently bought a Pioneer DVDR-109, which does DVD+R/RW and DVD-R/RW. Mandriva had no problems finding it, and one of those Linux programmes burnt a test data DVD without problem.
Eventually where is supposed to be some sort of update to the drive firmware which will allow the use of DVD-dual layer.
However, the firmware does a region lock if you use it to play DVD's back (not seen any firmware to unlock this "function").