My thing was that this is more of a "safari adventure" type vehicle for me. I don't really know anyone else to go offroading with for the time being, and it seems to me that it would be just as important for a lone explorer to be able to back away from his mistakes as it would be to pull himself through them. Id also consider one of those portable ones that you just hook to your battery, but if I have more than two people in the car there wouldnt really be any good places to store it.
However, thats not a bad idea about making the winch removable so I can just use the same one on the front or back. Though if I am stuck in deep water it would be kindof a pain to try to mount it under water! So I might just buy another cheap one to use back there.