I did a bit of checking around. www.imcdb.com (internet movie car database) has no record of Battletruck or it’s alternate title Warlords of the 21st Century. Also no joy on a Google image search. My advice is to watch the movie, see if you can’t spot a badge or something to tell you the make of the truck. In any case, I would then check Ebay for a truck of that make or at least one that looks similar. Start there. As for modifications, check your LHS for scale diamond plate, round/square tubing. Use household items to replicate features. I had a friend that made fuel tanks for a post-apoc build using cigar tubes.
Also, another idea for identifying the truck is to check the truck forum at www.scaleautomag.com, it’s another Kalmbach title,so its cool. Those guys might be able to help you, because they are serious car/truck guys. Let us know how it goes.
A Kenworth would work too. Both were made by the same company (Pacar) years ago, so there are similarities in hood and cab design. Definately looks like an interesting build.
HEY GUY !! I took a look at your picture and I do believe the answer is simplicity at best . From what I could tell you could use a PETERBILT or a KENWORTH standard long haul tractor . I believe you would be close with this choice . tankerbuilder