Tom:
There are many manufacturers who have 40' plus 5ers. If you are seriously considering a coach that large you may want to consider a MDT as well. Perhaps those who have large rigs can respond to a post you might consider making. You will be overwelmed with their responses I'm sure.
We have a relatively short rig at 27 1/2', Corsair Excella 26RKS, new this year. General Coach (Oliver, BC) make this make / model. They have a new unit out (4 slide model) that is 40' plus. The Excella is a basic unit that is well built (IMO), at least for what my wife and I were looking for.
Good luck and enjoy your retirement.
Roy