I made this exact table and it works great, but I don't think it'll work with the rollover couch. Here's an idea that may work better with the couch option:
Wow Groovy Dad, I really like that pull out, expanding table for a couch. It makes my idea of using an ironing board pretty cheesy, but the price was right ($2) at a yard sale, it's adjustable height, and it can go outside if desired.