Couch on DD LS

Hey guys. I need a little bit of help!!! I want to build/install a wrap around couch on the drivers side of my 09' LS DD. I have seen these on mastercraft DD and they look great and add some storage/seating space. Also thinking about installing a built in cooler. This is going to be part of my winter boat project.

1. Has anybody done this before? Could I use a couch from a wrecked/junked boat and where would I find one?

2. Is there or could I find a company to make the piece for me?

3. What type of material would I make the frame out of?

4. How do I secure it to the side of the boat or should i just fit it in tight?

I have seen Fat sac couches for this, but I want something solid. Might end up putting a ballast under it though. Thanks for any Help you can give!!