advice on buying a cruising boat
I would echo JeffH and say that for what you want to do, a sloop rig would probably be easiest to manage, especially with a roller furling jib.
Not sure I agree about the size issue. I did my first bareboat charters on a 40 foot Beneteau center cockpit and didn''t find it significantly harder to handle than 30 foot Erickson''s I''d sailed before. In fact it was much easier in ways because it had both roller furling jib and main sails, electric windlass, autopilot. But then, I''d spent a lot of time learning sailing basics in a Coronado 15 sloop.
Be aware that in many places along the ICW the channel depth can go below 3 feet! I have a 4 foot draft and have gotten stuck in the middle of the channel at high tide in Florida. I also have heard that in Georgia, the ICW is even more poorly maintained. So, the center-board idea has a definite appeal.
A good book for you to read is called Choosing a Cruising Sailboat (I forget the author), which discusses the "ideal" design characteristics of three different types of sailboats and explains them in detail.