Well My 2 started with cheap radio shack one's and my old RC10 and x-mods (lots of mods in them) that they got for x-mas (gen1's)

They both now have rc10gt's (nitro's) (they earned the money themselves) and i have been helping them learn to tune thier engines now that the break-in's are done

As a Dad i would say if he 4-8 i would really recommend eletric as a first one let him get use to 20+ mph speeds of a eletric (they are even faster with hop-up's) as he gains a better ability to handle the car let him pick from there if he wants the next BIGGER toy weather it be brushless super speed electric or a nitro

with what was said above the rustler/stampede or any other eletric for that matter alot of it is choice get him involved in it as well goto the LHS & the web,,,my kids and i spent almost 3 weeks doing research before they decided on what they wanted after talking with people here and at hobby shops