With all the cases of fraud on E-Bay, it's always refreshing to hear of a straight deal...
As new members, your first assignment is to practice basic and advanced searching, using Tab in blue bar above... You'll find a number of ideas for bed improvements, from re-upholstery with new foam to air-beds underneath to memory-foam mattress toppers.. Since it needs to be a couch as well, it is hard to add plywood "widener", but there are tricks to get a few extra inches of width, depending on model...
Be prepared for minor glitches and boo boo's, and then share them with the rest of us.. Try searching for the "dumb-a**" thread to see all the things fellow members have admitted to, which is a small subset of what we've really done...
John McG