I was down in Panama in 2001-2002 flying as a training captain for Aeroperlas. A number of the guy's I trained are now with COPA as FO's. They are all great guy's and quite easy to get along with.
Panama itself is fantastic. My wife, also a pilot, and myself looked at moveing down there but unfortunately did not. . .long story.
The city is coming along really well as a modern metropolis. It's a bit like a central American Dubai, but everybody speaks Spanish. The lifestyle is great, fantastic restaurants and bars; Casca Viejo and the area around the French embassy are a gas. The beaches are great and the people are friendly. You'll get along easily but let me know if you want an introduction and I'll forward the email address of a very good friend of mine, Columbian, who is an FO there. It helps if you speak Spanish though. He might have some insight into the interview process as well.
Good luck with it mate, you're going to love it.