Are you using the "what fits my car?" feature at Crutchfield? I don't think you could go wrong choosing the Econoline as the model but you could compare some other Ford package features with your RV and then use that package as a base line and insert it into "What fits my car". AFAIK, that part of Crutchfield selects the DIN size and any adapters needed, controls within the head unit for locks, alarms, and other accessories, and anything passed through the head unit, electrically, for the vehicle. Of course, it also selects speaker sizes and types if you're shopping for that.
In most unsophisticated vehicles, choice of head unit is easy. Choosing one for, say, a Jaguar or other sports car can be treacherous. I own an F-250 and have a Pioneer aftermarket head unit installed. It was easy to do and selection was bog standard.
Good luck with the installation. BTW, there are adaptor harnesses sold to mate most aftermarket head units to the vehicle's original plugs. I'd suggest to get one, it makes everything very easy.