Dont waste your time with nitro, its noisy, messy and just generally a pain in the arse.
Brushless electric is the way forward, its almost silent, as fast if not faster than nitro and is charge and go.
I have a few different cars, a HPI savage 4.6 (nitro) Traxxas Stampede VXL (Brushless) , hyper 7 (nitro buggy) and a Associated B4 buggy.
I have just finished building this for my 7 year old, this was his first time out with it.
I did enjoy building it and going back to my youth, my stepfather owned the modelshop in Cromer, Norfolk so i spent most of my time in the shop building and fixing for people.
Flying (Heli’s and fixed wing) is my main hobby.