Tony, the transmissions are the same between the two but that ends at the final drive output ratio. There is virtually no cost difference between the two versions because it is basically the factory swapping out one part for another: 1/2 shafts, coupler, TCM, etc. AND different programing so all of the stuff works together, i.e. engine speed among other things. Even if you could get all of the pieces you would still have to do the programming and that comes from your VIN number and can't be changed, we tried it.
Goebel1 and I had a labor of love trying to go the other way in the AutoStick Conversion
thread. I had the easy part of going blind looking at the wiring charts for hours and days on end while "G" had the frustration of doing the wiring, mechanics and trying to get some help from the dealer and the Engineers and my VIN number. I did ask the Engineers when we had our Q&A Session
with them if they had any plans to make a retro fit kit for the the MK's to convert to an Autostick on the FWD's and FD II's and they said no.
If you want to have the FD II then you need to get it from the factory. Very disappointing to me since their doesn't ever appear to be a chance of retro fitting a Compass with FD II. Maybe the bone yard will supply me with the needed parts, eventually...