Conversion Kits (flatpack or pre-built) for a MWB

I've found loads of flatpack options for VW Transporter or Ford Transit Custom, as well as some for larger vans.

I'm however in the market for a MWB. Either 2020 Sprinter, 2020 Crafter or 2022 Transit. I want to build it myself, but I want to save some time by using pre-built units that have already been scribed to the specific van.

Does anyone have knowledge of these for the MWB vans above? I'm struggling to find much.