Do try several good mattress shops. Try out the firm foam ones. I am not even sure, that off brands do not carry these firm ones now. I love my foam one, and wouldn't go to a sleep number bed for anything. Besides you are paying for an adjustable kind, once you adjust to what you need, the controlls are no longer needed.
Start your search, I do bet you can find something these days, expensive or not, that will help both you and your wife. I wish you all the best. ginnie