Dave,
For your situation, a BBB is probably the best choice. I looked at one but couldn't justify the $ when I could buy a new Polaris Ranger for the same amount of money. Make sure yours has the fixes done to waterproof the connections, they are building them differently now but if yours has not been built in the last 3-6months it may have the "old" connections and those had problems with water when crossing creeks or bogs.
There are a number of folks building electric UTVs so you might check around. Some of these are rehabilitated golf carts and some are not. I've got about $3,000 in a cart that was lifted with better tires, controller, cables, F&R switch and solenoid. Because I have the Ranger and knew I could pull it out, I've had it in places that I really didn't think it would go and have never been stopped. If you think about it, all the weight (batteries, motor, passengers) are over the drive wheels. I don't know how severe the terrain you'll be in is but you might check around to see what is available already fixed up. If you do a little reading on them, they are mechanically very simple, much more so than the Ranger or Mule.
If $ is no object an/or if you are going to be in the worst possible muck, get the BBB. They are expensive but are the best electric option out there.
Good luck on whatever you choose.
Paul