The first thing I'd do is find an independent tech that can service it. They will give you insight into what to avoid. I would also be open to other brands.
We have an interchange MD-8 and after running it for 11 years I would 100% buy one again. I might look at the airjet if it has better insulation in it...that is my only gripe.
the best person to talk to is Winston if he's still active. his handle is californiadreamin