Personally I wouldn't touch a marinised ford with a barge pole, some people like them (affectionately known as a bus engine) but can give problems if not used properly.
Possibly the most common engine out there. A grand workhorse and will run reliably clocking up huge hrs. The cheapest to rebuild if you ever need and heaps of different manufacturers around the world that made the parts to marinize them, so parts available everywhere. The famous name in NZ is Lees and the guys that took the Ford and commercially Marinized it for the World is Lehman Mfg in New Jersey, whom used the Ford UK engines.
There are many versions of 4cyl and 6cyl engines. And I do have to say, I have come across a couple of Boats that in fact did have old Ford Bus engines in them.
Just not as refined as the more modern day engines of course.
harrytom, yes you can buy engines of just about every cylinder number. 1, 2, 3, 4, 5, 6, 8, 10, 12, 16. I do not know of anything with 7, 11, 13, 14, 15, 17, or greater in number.