The cost of labour for the physical work as well as the R&D required for that would be astronomical. Id imagine the tech would want to be paid strait time as opposed to flat rate, which can add up very quick.
If you have both vehicles, and the time to strip them both down and transfer harnesses and driveline components, anything is possible. You just gotta make sure you have good schematics for both vehicles, and lots of different coloured highlighters and tape to flag and separate the harnesses (that need to be integrated together), then get some good quality solder and heat shrink, and then merge the beast and foul as one!