There are quite a few of those engines in
service. I have not owned one in a boat, but have worked on the automotive versions, and found them finicky. They leak worse than a detroit diesels. If you need
parts for the basic engine, good luck, but if the engine is in good
repair, and
maintenance has been good, this should probably not be a deciding factor in
purchasing the boat. Unless, of course, it is a
motor sailor that will be relying heavily on the engine.
Almost forgot, two other points. The peugeot engines are very loud, and they are a car engine as opposed to an industrial engine, so running for long periods of time at a set
RPM is not what they were designed for.
Ford
Lehman was also one of the companies that marinized these engines. These parts can often also be hard to find.