IIRC correctly those are also used as SCUD launcher platforms too. I heard that the starting process for the engine is a bit complicated. I think it involves heating the cylinders like a glow plug system, but then using a pressure system to push the pistons down to start it up, kind of like a boat. But I can only somewhat recall the article on it. I think it's a 39L engine?
I think the HEMTT is nicer because it's fairly road worthy. Unfortunately they are rare in the US as surplus, but obtainable depending on your pocket book, you can probably even get the better commercial versions from Oshkosh.
I think the fire truck variant would make an awesome expo vehicle that would be relatively affordable to fuel.
Still, I bet the Scud Trucks are more obtainable. You can probably even get a missile too, you can probably pick one up in any Eastern European Country. Like the ad said, $40,000 per truck.