Suggest me a fast, belt-driven nitro kit
 

I am trying to create a new invention in the energy industry, but I don’t have a good grasp of the energy technologies out there. I thought RC cars would be one vehicle (ha ha) for learning about some of them. For example, how do the chemical batteries compare to nitro tanks in energy storage?

With that goal in mind, I am trying to get a feel for the range of RC cars out there. I want to buy one at each extreme:
•One fast and one high torque
•One RTR and one kit
•One nitro and one electric
•One belt and one gear (if belt-driven cars tend to get too gummed up when doing off-road I am fine with skipping this spec)

Given that this is the nitro off-road forum, I was hoping to get help with suggestions for my fast, nitro-powered, belt-driven kit.

Here are a couple of other considerations I had:
•My budget is $200-$300 for each car.
•I would like cars that are compatible with a lot of parts, as I see myself upgrading them over time.
•I would like to be able to run the car all year round without having to go to a track every single time I want to use it. This makes me reluctant to get the on-road cars. Though, if you can think of a way I could run an on-road car in the winter, I would be open to it. I live a little east of Trenton, NJ and didn’t see any nearby indoor courses.
•I would like to have cars that would be allowed and competitive in races. Being competitive in races is less important than staying in budget.