wbill76, I had the same thoughts as you. I was thinking about letting in the US stuff but then came to the same conclusion as you did. I would open it up to the Opel maultier though.
There are quite a few variants including ambulance, fuel truck, flak and even a fire truck.
I know there are two conversions for ambulance and I am pretty sure that there is a fuel one. And Its probably not hard to scratchbuild a flak version.
Well, we'll have to see how this turns out. Somebody just opend up a Cargo Truck GB in the GB forum.