Ok guys I have a question about the couch on my '87 311. The boat has the rap around couch with the walk way in the center. I want to build a insert that would make the area into one big bed

Anywany I want to know of anyone has done this before. I also heard that Formula had made an option for this on the boat. I tried to call Formula today but it was to late. I have attached a pic do its kind poor but you can get the idea. Let me know what you guys think.