I talked to a regional Montana salesperson at Keystone recently and he said they are working on replacing all air beds with mattresses in the new models. He also said there is a problem with doing this in the Front Lounge models due to slide clearance.
Someone here on the MOC recommended replacing the air bed with this:
http://www.walmart.com/ip/Modern-Sle...Queen/21287287
Since we travel with our teenagers and those couches are their beds, I'm going to try one of these and see if it's a good replacement.