It really wouldn't be too hard to just plan this and do it yourself. You have a lot of time to do this (almost a year and a half). If you like the French side then stay on the French side, and if I were you I would make online reservations at the newly refurbished Palm Court Hotel which is a very short walk to Orient Beach. Plenty of restaurants around, but Grand Case and the restaurants that will be open there by 2021 is just a short 15 minute drive. Day trips can include Loterie Farm and even Anse Marcel if you wish to experience another very nice beach. I'll assume you'll be renting a car, and if so I would recommend either Hertz or Kennys. If you don't rent a car, you can always take a taxi from the airport to the Orient Bay area, but the ride will cost you around $35 USD. Then, you'll need to take taxis for whatever day trips you plan.

When it comes time to depart for Anguilla, drive or take a taxi to the port in Marigot and book the ferry roundtrip for the dates you have set aside. The ferry runs from Marigot to Blowing Point on the south side of Anguilla and it departs every 45 minutes or so (or at least it use to). The cost is something like $20 per person. On the southwest coast of Anguilla there are many nice hotels to choose from, but the prices vary greatly (from expensive to ridiculous). Might want to check out the Anguilla Great House Beach Resort which is a short taxi ride from the ferry point. It's not a four star hotel, but it's relatively nice and right on Rendezvous Bay and will run about $290 per night in February.

Sometimes things work out better and are less expensive when you plan these trips yourself so it's something to ponder.