Burl, a handyman/electrician could add that pretty easily. The most skilled part is cutting the opening. After that it is just grunt work and very basic household electrical wiring. Since the power center is right next to it, the wire runs through a hole I drilled in the cabinet shelf, then through the opening on the floor by the wheel well, then over to the power center.
If you have it done, I would recommend the person take a couple of moments to make a backer strip and glue it behind the bottom of the opening. The paneling is so thin otherwise that I think the screws might eventually pull out. I used a razor knife to cut the backer strip from the cutout that came out of the opening. I located the opening so the upper screws would go into the structural wood at the top.
The materials are probably $25-30 at big box prices. The labor for a pro is probably an hour or so.
Re the beds, I recall you are 6'5"? Unless you don't mind your feet hanging way off the end of the twins, I think your wife is right. I'm only 5'9" so the twin will be barely okay for me.