I replaced mine in late 2018 prior to FlexSteel exiting the RV business. There was a limited selection (4 styles if I remember correctly) of seats due to the size and base bolts requirements of a Class C motorhome. The ones I chose are extremely comfortable with adjustable Lumbar and other adjustable aspects (I haven't made more adjustments but I think the armrests and the chair back sides and back tilt are also adjustable) along with the drivers side pedestal being 6-way electric for other adjustments including base tilt as well.
In any case, I was told that the larger Class A seats will not fit due to the floor height, base bolts, reclining room and a few other issues.
Another thought is that the seats I did install are similar to those in a Class A in size and comfort based on me sitting in a few Class A's over the years although I suspect they are a little smaller. Also, I don't see anyway possible that the ones I purchased could ever swivel due to the size of the seat even if I had a swivel pedestal as the seats are only a few inches away for the sidewalls of the RV cab. I have not sat in or checked out the newer Class C's with swivel seats, however I suspect that the seat area must be smaller or something in the swivel is different than simply swiveling at the center point of the seat itself.
Probably what I would do now that FlexSteel is no longer an option is consider having the seats reupholstered with Ultra Leather (that is what I chose and from my research it is the best material to use) and while they are reupholstering them then perhaps they could add more foam underneath the upholstery if needed or make some changes that would provide more comfort for you.
Other than reupholstering, you could call around the few places on the internet that may have Class C seats, perhaps
https://www.braddandhall.com/product...idCategory=122
Good Luck and Welcome to the jaycoowners forums, CA