Still experimenting with the best bed set up for us. Going to try the two singles, with 4.5" (current cushion thickness) width extension. These are the two wooden extension pieces that will be screwed down to the current slat lip (easy to remove if we decide to change back). I need to make two 4.5" square bolsters to go under the couch back cushion/behind the couch seat cushion. I have the foam and I have the fabric! I have not, however, used a sewing machine in a few decades, so will need to check some youtube videos on how to cover a square bolster cushion. Any key tips from experienced seamstresses/tailors appreciated!