We have not replaced the couch in our PC but we did replace one in a previous rv that we owned. We bought two theatre seats from 4seating .com. We bought the Seatcraft Napa HomeTheatre space saver two seat set. It was a power recline, had led lights, cup holders, charge ports and small trays that you could put in and out. The seats measure 65w x 43H x 40D. They were grade 7000 leather. We had them for four years before we sold the rv and they still looked like they did the day we purchased them. They were extremely comfortable too. I had searched a lot of places before I found something that would fit and was not one of the cheesy, peeling seats sold for rvs. Just thought that I would give you one option that could help you. Good luck! I’m sure others on the forum will have some other options for you.
I just realized that you need something that is 54” wide so the above won’t work for you. You may be able to find something else there that will work for your space.