Din is 7x2" and Double Din is 7x4 inches.
The Din and a Half size is 7x3 and was used on some Chysler products. No longer available BUT there is a kit for For Chrysler products which allows you to buy a widely available DIN size radio and then have a small finished pocket beneath the radio.
Now the trim kit is specific to the Chryler mount but my guess is that with a bit of creativity you could "adapt the adapter" to your dashboard for a finished look. Or...any car stereo install place could do it for you.
Just show them this Metra kit and see what they suggest after looking at your coach. Metra 99-6504 In-dash Receiver Kit Fits select 1998-2009 Chrysler, Dodge, Plymouth, and Jeep vehicles — single-DIN radios at Crutchfield.com
I heartily second the notion of using Crutchfield for your product selection. They are great and not just shippers of product.
Based on your described needs, I would recommend the Alpine CDE-124 as an excellent choice if you go for a din sized unit: Alpine CDE-124SXM2 CD receiver with included SiriusXM tuner at Crutchfield.com