Re: 4 speed auto in XE Clevo ??
I thought you were looking at a BTR 4 speed auto, not a C4 type trans??? Why do you compare a modified C4 with a standard AOD? If you want 4 forward gears, the C4 doesn't get off the starting line.
OK, the C4 is an excellent transmission when modified, no question about it. The AOD is based on this transmission, hence it's easy interchangability.
AU$3-4k for a rebuild? Buy an overhaul kit from e-bay (about US$120), and the Max Elery Ford transmission manual and do it yourself. Get a shop to set the critical end float settings if you want. While overhauling, add a few bits to boost the strength - wide OD band, a shift kit, one piece input shaft maybe and you're done.
Or, buy a built trans from Baumann or Lentech. Prices are about US$1900 from memory. Easily capable of handling 350HP. What's the AU$ v's US$ at the moment? 0.75 ish?? So your're looking at <AU$3k including transport. It may seem like alot of cash, but quality and knowledge costs. The payback is trouble free cruising.
Now compare this AU3k with the cost of purchasing the BTR you were originally looking at, reconditioning and building the btr to cope with 350HP, and getting all the electronics to work.
At the end of the day, it's your call. The C4 is the lower cost way out, but you can't run 4.5 gears on the highway. With an overdrive gearbox you can. How much fun are those 4.5 gears in 1st and 2nd????
Good luck whatever you do (I'm tremec tko manual myself)