We had custom slanted cushions made (affordably) for our dinette. They really transformed it, both for sitting normally and for lounging length-wise.
I'll be taking the 2300 out of storage in January to go to AZ. I'll try to remember to post photos, dimensions, and source information. I ordered the OEM upholstery fabric from the supplier in Indiana, and had the foam company make zippered upholstered cushions. Looks like it came that way from the factory.
2014 Sunseeker 2300 Chevy