Aaron,

A unimog would certainly be a possibility, but if you ever drive one you'll probably agree that it is more like driving a tractor than like driving a truck.

If you want an MB truck you can get around in well and use it on an every day basis, your best bet will probably be something from Europe. There are so few MB trucks of the size you're looking for in the US, it will be difficult to find one.

Good luck,