That's actually an excellent question. In my case, I had dealt a little bit with the shop & mechanics I currently use when i was a club member as they took care of the club plane. Now I'm in a different club, and they use a different mechanic who I've not met, but I also heard multiple long time-owners say that she's great. I think word of mouth is probably the best way to figure out who to even approach. After that, I feel like just talking to them in person and looking around their shop will tell you a lot. Before I bought my plane I had a discussion with my current shop and told the DOM what I was buying and that I wanted them to take care of it. We talked about the plane and he agreed there would be no problem as they are very familiar with Pipers, and they would have time to work on her.