Re: Aft Cockpit vrs Center
We've on our 5th boat, boat 4 was a 52 center cockpit. All the others were aft cockpits from 22' to 38.
Center cockpits in our opinion get better as they get bigger. They do have the advantage of a separate aft cabin which can be very nice especially when guests are aboard. Also, we've found the aft cabin to be a reasonable place to sleep offshore. The galley is usually situated between the salon and the aft cabin, which is nicely midships and narrow with good support for offshore meal prep. If properly designed, engine access can be pretty good on all sides, but this can get messed up too as the boat gets loaded up with systems (as in any boat).
As the boat gets smaller though, the disadvantages outweigh the advantages in our opinion. You are driving closer to the pointy end of the boat, and are up higher. Can be wet and uncomfortable offshore. And then the extra cabin space and salon get smaller too. Generally, to make the interior work, they start looking more like wedding cakes (this is obviously subjective).
If you are considering a center, we'd recommend you buy something at, near or above your max length to minimize these disadvantages. If you are buying in the 30's, we'd definitely stay with aft cockpit.
All of this assumes you'll be doing some offshore passages to get to the Caribbean. If not, it doesn't matter as much, more a matter of taste.