I'll first say that its a really fun class, and you guys will have a blast. imho the simplier the rules the better. Here is how we ran it.
Truck- Box stock, with the only exceptions being the body and rx. If it came in your box you can use it, no other mods except oils.
Battery-This year we ran 6 cell nimh only , but I think we are going to expand it to lipos next year. We found the lipos do have better punch but the weight reduction made for less traction. Top speed was about the same.
Thats it, really easy to police