Axion/Scope/Rize shower surround

[kltk1]

Hi, folks. I'm looking to build a van with a rear bathroom like the Carado Axion/Thor Scope/Rize 18M. I'm having trouble locating a source for the shower surround wall that accommodates the wheel well on a Promaster 136". Does anyone know who the supplier is for Thor/Carado? Or a supplier with a product like this? Any help is greatly appreciated.

Note the lower right of this picture below and behind the toilet. See how the wall is formed around the wheel well? That's what I'm looking for.

Thank you .