cmj:
Sorry that I can't offer you a name, but I can suggest a couple of options that you may not have thought of. Since many travel agents won't even bother to sell airline tickets anymore, you may have to join the rest of us in figuring out how to do this on line.
I was in a travel agent for nearly 20 years. Got out of the business in '02, because it went to "H*** in a hand basket" after 9/11.
When I travel myself these days, I start by going to
www.orbitz.com. There you can find what airlines fly between your points (MCO, STX), and the display will tell you how many stops/changes, etc. And, you can get a good idea as to prices. I then go directly to the airline's site that best matches what I'd like, and manoeuver around there to see what works best for me.
I frankly stay away from the discount sites (Expedia, and such), mostly because I have never quite trusted them if something goes wrong. I know, though, that many people swear by them, because there definitely are some very good deals.
That's my usual method.
You should know that it is, so far as I know, virtually impossible to get to any island in the Caribbean without going through either Miami or San Juan! American does (or did) have nonstop service from Orlando to San Juan, which would avoid the horrors of Miami. And, American (or American Eagle) used to be the most common small-plane carrier from San Juan to the islands. I haven't ever flown any of the routes, preferring to go by cruise ship, but my agency booked clients all over.
Getting there was always a nightmare!
SWR