I think that most dealers would avoid this installation for liability reasons but you never know till you ask. I can find out from my friend in Maryville who did his conversion and they may be able to tell you how to get engineering approval from Forest River and get any Forest River dealer to do it. I'd try a mobile rv tech if there is one in your area or call a local propane business and see if they have a technician willing to do it.
When we were in Myrtle Beach there is a place across from Ocean Lakes Campground called Camper Connection and those guys were installing a motorhome fridge out in the parking lot before the retail store opened.
If you want to tackle it yourself, I bet you can, the instructions are available online: