I would re-think excluding the production boats for your intended use (you haven't mentioned all production boats, but my sense from your post is that you think they are not up to the task). Putting aside taste and the intangibles of what type of boats you like, production boats (whether they be Jeanneau, Hunter, Catalina, Beneteau, Bavaria, and the list goes on) can handle the Chesepeake, the US east coast, Bahamas, and Carribbean without trouble. If you plan to do extended offshore work, or certain other missions such as high lattitude sailing, then the production boats are less suited. But for island hopping in the Carribbean, including getting to/from, they are fine, and in fact may be better suited for a variety of reasons that have been written about extensively (e.g., more comfortable at anchor
, faster, less expensive, better manners around the docks).
Also, you mention that though you think they are OK for charter you think they are not sufficient for Carribbean cruising. Keep in mind that charter boats get used more often and are abused like few other boats. Plus, they all are delivered to their charter bases on their own bottoms, which for most mean they've done an ocean crossing of one sort or another.
Anyway, there are plenty of boats that have better fit and finish, are more prestigious, have higher build quality, and are just plain nicer. And if these are attributes that are important to you (and that's certainly a reasonable perspective), then I could understand not wanting a production boat. But don't exclude them because you think they are not suited or are incapable for what you are planning to do. That would be a mistake, in my view (not to mention possibly over-spending precious cruising kitty dollars).
A further thought too, which is why I write this. You are looking for a boat that can house 4 to 6 people, and it must have a swim platform, you want it to be 8 years old or newer, and you want to spend only 200,000 to 350,000 (you mention 38 to 43 feet, but 4 to 6 adults living in that space for any period of time is going to be very tight). There are precious few boats that are going to fit those parameters, and most of them are going to be production boats in one form or another. Just my view, which is worth what you've paid for it.