K - You should spring for a copy of Nigel Calder's
The Cruising Handbook. Half the book is devoted to the boat and it's systems. Very good reference guide.
While individual things affect a boat, it is how they are put together as a whole that is most important. Here's a link to a listing of "suitable" offshore boats
http://www.mahina.com/cruise.html with a lengthy commentary on boat selection.
And to answer your one specific question, a cutter is a double headsail sloop.