Fresh meat, fresh meat, fresh meat...yeah, ok, we like newbies.
Back to business. If you REALLY want a road car, then go with a RTR. In the case of the RS4 RTR's, they can be adapted to take all the SS parts when you get serious about racing. SS parts include a 2 speed transmission, turnbuckle suspension, etc. Plus, a hotter motor.
You still have not responded to the proposal that you may want to consider a truck of some sort unless you are comepletely comvinced you will always run on clean, smooth surfaces.