For your use I would take a look at the PDQ "power"
catamaran. I forget if it is 32' or 34' long, but it has WAY more comfort and space than most boats considerably longer.
Being a cat, it gets really good mileage, without having to get on plane, and with twin engines you not only have a backup, but incredible close quarter maneuverability. Great visibility too.
If you wish, you can run most of this route without doing
marinas, because the boat's shallow draft will allow you to just pull over somewhere safe, and if you judge the tide wrong, as we did once, you just sit there until the next tide floats you off. This is a huge advantage on the
ICW.
I have run this a number of times, and it is mostly protected. The Chesapeake and NC Sounds can get nasty in a storm, as can the Sounds in Ga and N
Florida. From there there is a bit of open
water in the Keys and
Florida Bay, then, after Cape Sable on the West coast of Fl, you go ICW all the way to Tarpon Springs. From here you pick calm
weather, and do ONE overnighter to the panhandle, because the "arm pit" is very shallow and best avoided. If you watch your
weather, you can avoid the drama almost entirely.
Good luck in your search... Mark