RTM also = ARR... race rollers...

Think of the 1/8 scale nitros as... Ready to convert to brushless

As far as general requirements for Rolling chassis... they need a radio with 2 servos (horns normally come with radio/servos), engine and exhaust. Sometimes they come w/o tires but come with wheels so you can pick your own treads to suit your needs.

My cane is going under a major surgery... its getting a powerplant transplant. Instead of fuel, it'll be running off of a 4s lipo and turning a good 50,000 rpm.