This sounds lame I know. I'm a big mechwarrior fan myself. Instead of trying to make a mod to do that In JK why not just play Mechwarrior. There are several games. Though there isn't one where you can be infantry on the ground lol.
Maybe they should make a Battlefield 1942 version of Mechwarrior. Or maybe you should take your mod idea to that game. I think it would be better suited. Maybe you could get some interest in it and do something like Galactic Conquest with it? BF 1942 has really good mod support I think.
Now that I thought about it a BF 1942 Mechwarrior mod sounds pretty good maybe have 2 or 4 mechs for each side and different vehicles from the universe to battle them with if your not lucky to get in one.
Nice model though....