Based on our experience with ASAP Truck Rally Team (www.asap.be/rally), the Mercedes Unimog might be a good option to use as a basic setup for our Solar Rally Truck project. The latest technology from Mercedes is bundled in the U5000, but other models like U1300 or U416 might also be a good option to start from. Youtube-member ExpeditionDesign simulated an U5000 example (still non-Solar of course ;-):

Unimogs are wellknown for their robust construction, very versatile usage, very special drivetrain with portal axes and support by a world-brand.

But their might be other interesting brands like Bremach (small & light trucks) related to Iveco. Or we also think about Ginaf (based on Daf).