what will he be using it for? field riding? track riding? racing?
bambino bikes are great for kids, semi auto 90cc-110cc, nice and quiet (as this can often scare little kids more than riding).
Pit bikes take maintenance, and lots of hard work to keep on top of them - but if you do they can be very reliable. The lower cc engines in these bikes dont make huge power, so do tend to be quite reliable.
strip the bike when you get it, locktite all the relevant nuts and bolts, change the chain for something japanese or british.
They are great little bikes, and bambino racing in supermoto is really growing