Bought a used coach that came without the sofa. We have the two of us and our son using the motorhome just about every weekend of the summer. We have 72" of width available in the slide for the sofa...
I ended up buying a convertible sofa from Walmart which just so happened to be the right width. Not super comfy, but the boy likes it. The slide is higher, and the front feet land outside the slide. So I added rollers to the front feet, which seem to work great using the slide. And they add up to about the right height.