All three brands are good coaches. Some are a little over rated, but still they have built good reputation over the years. Even at that there are still some lemons.
As to Country Coach not in business anymore, I would not worry to much about those coaches that are orphans. You can still get parts. Like somebody else mentioned, the chassis on most of these coaches are the same. Engines and transmissions are items that you would not have any problems getting parts for them. And end caps would be no problem if you had an accident.
But if you look real close. The quality of the Heritage, Eagle American coaches, then look at the Newmar and Country coaches. You would see how much better the house part is on the American coaches. Now I know there are many that will disagree with me, but this is just my opinion.