Before starting this project
, get on some 30' monos, cats and tris. 30' tris have very limits space inside. Make sure the wife can see the difference and understands.
While there is no official definition a Caribbean
circuit isn't starting smaller in my mind. There are multi-day passages, lots of boarder crossings/officialdom, no access to US facilities and services, etc...
Smaller in my mind would be local coastal cruising for a week. A step up might be a run down the ICW
. Caribbean loop would be a step beyond that just short of ocean crossings.
I'm not trying to scare you away but if she isn't ready for a drastic change in a very small boat, you may be shooting yourself in the foot. If she hates it, it can quickly become a choice between her and cruising.
I would really suggest trying out the lifestyle in a used boat
(get one rough around the edges so you can still get your hands dirty). Plenty of cheap
older tris around. Then when you know better what you want, build the boat of your dreams. Far too likely you will build a boat and then get caught between the love of your handiwork and what you really need to cruise