Charles and Linda,
I hope you are an effective technician. If you are not, you will have to find one. The newest of our coaches is 45 years old and they require maintenance as you would have expected if you bought a vehicle at that time.
The best part of being a GMC owner is the community it connects you to. So, before you do much else, go to the GMCMI website and grab a copy of the "Black's" aka GMC assist list. Make contact with a few people.
The best way to get a good GMC is to locate the websites for all 16 local chapters and keep a close watch. Sometimes they are available but do not come up for sale that soon. The membership is aging and many have coaches for which they would like to find a good home. Remember when you speak to these people you will be discussing a family member.
When you get real close, build a sigfile like most of us have so we know what is happening.
Best of luck
Matt_C