Hi Marcus,
I think the MAN 5to is a good choice for begining tttt. The Prinzgauer should be the second project. It is a little bit difficult to power the two rear axles.
You dont need a front drive axle. 2wd is more robust and the circle of turning is better. Even this is very important for offroad driving.
A 4mm Motor is to small. I suggest you the 7mm motor. The 4mm Motor is good for a winch oder a 1:160 scale van.
If you looking for a good driveline just look an
www 1zu87modellbau de. There is a new ready to build in 1:90 gear availible.
There is also a very cheap speedcontroler "ER100" availible. Just better than a servo circuit .
But you can also use any other speedcontroler in this size. The difference is mostly a build in brake and reverse-driving-light port, or a programmable characteristic.
The HLBT is a controler to switch driving lights, direction lights and two flashers. It comes with a manual (also to download at
www 1zu87modellbau de ) that shows you how to wire up.
I hope my english writing is not to bad, if there are some additional questions just feel free to ask.
best regard
Thorsten
www mikromodell de