A revo is a good choice, most people are happy with them as monster trucks.

Like new guy said though, if its missing alot of parts then it may not be cost effective to put back together, or you may be discouraged at all of the parts you might have to buy. Best thing to do would be to get him to do a inventory with pictures.

If you have questions you can post them here on chitown and those more familiar with Revo's may be able to tell you what you are missing and what it might cost to put it backtogether before you buy it.