Tactically, he needs to get into melee as fast as possible, while mitigating the damage from being shot at. With what he has I'd put the Nobz and the Warboss in the truck, with no less than heavy armor. Extra armor on the trukk with a ram, so when it gets stunned in can keep moving. Pick a flank with the boys as the pivot and run the trukk up one side. Shoot, but expect nothing. The grots should run around behind things and be annoying, or run in front of the boys to provide them 5+ cover.
The first thing I'd add (besides more boys) is a Warp head. Easily converted or aquired, use him to buff the boys.
The next thing I'd add is some kind of mean, solid threat. Deff Dred, Gorkanought, MegaNobz, something like that. Another boyz mob is more practical and long term useful, but hardly "fun" in the short term.
The main thing will be roll with the Theme of the force. Orks spam well, but many different units don't work as well. The plan has to be simple, with lots of redundancy to back it up.