Wait, I'm confused... you couldn't stand in the sports mobile pop top (prototype??) or the plain jane 159 high top (which is like 6'4" internal right?)? I'm really keeping my eyes on a 118 low roof diesel with pop-top/custom camper interior as an eventual replacement for my '72 VW westy. I'm 6'2" and standing up is essential while camping to me. Kinda the Hymercar Sydney.found out I'm too tall to stand up completely in the cargo area (I'm 6'6")
At one time the Sportsmobile site indicated only the 136 low-roof would have the Penthouse option. The latest info also suggest the ProMaster Penthouse will have 6 feet of headroom when down and 9 feet when up. The shorter 118 wheelbase may have to come from a different builder.