If you like to start with a used trawler in a bigger size, I think the Hatteras fibreglass Long Range Cruisers are good value for money. I don´t remember what sizes they came in, but from 55 to 65 feet I guess.
There are many producers of trawlers and explorer-like vessels in small sizes today, which can be nice live aboard boats if you want to try that route instead of buying a place down there.
I think you should buy magazines like Passage Maker and learn the pros and cons of the different boats, building materials and issues like single or twin engines.
Or you just buy a nice smaller boat, maybe of the lobster type, and get your own experience to start with?