If you want door tables, trim pieces, etc Sportsmobile doesn't sell that stuff individually. Most people just make it themselves or have a cabinet maker help out. Gives you a chance to use better materials anyway. The one benefit of the #vanlife movement is that a whole lot of people have gotten creative with their interiors and they are happy to share the details on social media.
One can get parts not listed on the website from the SMB West/Field Vans, formerly Sportsmobile Store. Just ordered something yesterday. Don’t know if interior build pieces are available, but I have ordered T-molding before.
2008 GMC 3500 Quigley Weldtec 4x4 Savana SMB
2006 BMW HP2 Enduro-Sold