I just saw RC4WD has a 1/10 pulling sled. It would be cool to design one for 1/24 scale stuff. I mean, really cool. Over the last year or so the 1/24 scale market has gone kinda crazy with new stuff.
But a regular driven semi, and a pulling tractor... yeah, that could create a need for a lowboy...
That is really cool. Since you are using a 1/24 scale semi truck body, I'd be all over that chassis.
But I would probably try to get a Furitek system in it if you wanna get crazy cool. They have a few options for transmissions and motor combos, as well as the best ESC's in the business for...
I have used that exact method to paint a motor. I used a brown base coat, and a red top coat, and rolled it around my fingers while the red was still tacky. It looked like a rusty old motor.
This is going to be a killer project!