I'll second the comments of TC regarding Medeco locks. We have them on the
cabin and baggage doors of our Arrow, and they work (and wear) very well.
The one quibble I have is that the Medeco keys have such huge heads that
they provide enough leverage to easily break the key if the lock is stiff or
frozen. Getting replacement keys is a real bitch.

Arguably, the Medecos are "overkill" (as TC says, they are really to keep
honest people out) but everything else available is junk.

--
-Elliott Drucker