Hi Truckian,
just take a look at the "slow flyer" scene. There are a lot of small components availible so you can buld your truck.
Or try out
www.mikromodell.de (a small english version and a large german site, I am still busy in translating ;-) )
I hope youll find some hints there
What special kind of SemiTruck is your favorite?
best regards
Thorsten
www.mikromodell.de