Nitro rc cars require a lot more knowledge, skills and manintance, it's not really a personal preference it's it's just a carastics of those types of engines. There has been loads of cases of noobs having tuning issues and not knowing what to do. Some people even have very expensive learning curves. Tuning is a skill, it's like riding a bike, once u know how its easy but learning can be very painful.... And some people never learn. My learning curve was over $230 with a total of 3 piston/sleeve sets...
because of those issues a basic RTR electric kit is going to be problem free for a lot longer, something like a traxxas rustler xl5 brushed with the supplied 7cell nimh and wall charger is going to be plug and play, and with the addition of Traning mode it would be very suited to a 8yo learning the ropes.
allso another reson I recomend electric is reverse.... When playing in the back yard or even a park it really does suck not having reverse. Sure u can get nitro's with reverse but they are generally expensive and troublesome
I have total respect for ur passion for nitro engines, its great. But I feel they are a more for people with intermediate skill level.