The AF flight is also operated as a DL codeshare, so that should (in theory) make it easier to book, manage, and accrue miles. I used vouchers to fly MCO-PPT on DL/AF, and all of the flights were booked on Delta.com.

Keep in mind that the AF return flight leaves early in the morning (or at least it did last May), so you may need to get a place to stay on the main island anyways. Send me a PM if you'd like a recommendation for a terrific (and relatively inexpensive) B&B with free airport transportation.