I had similar ideas, but wanted my table. I bought a pre made laminate at Lowes and cut it down to make a pull out counter, stove cover with cutting board, and fold down counter. I used fold up beverage holders with arms to keep spills down at the couch.
Not a perfect match, but no one has noticed yet. The cup holders fold up when not in use so they don't get in the way at all. Bought 'em on Amazon.
I went with soft close drawer slides on the pull out counter. It hasn't come open at all during travel and it stays open when parked. We added closing it to our pack and leave checklist because if it's out, you really wouldn't want to close the slide!
Draw pull, 4' pre laminated counter, eve support, drawer slide, and hinge came from lowes. Also in the first pic you might notice I swapped out the faucet for a nice residential pull out, also from lowes. The cutting board over the cooktop is from blood bath and beyond.
Thanks for idea to split the sink cover. That will happen tonight!