I have no experience with the Leopards or Catanas, but have sailed numerous Lagoons and FP models. Without knowledge of the toy packages, my preference for the Grenadines at that time of year would be for the Lagoon. Approximate light displacement for a Lagoon 45 is 33,000 lbs and a Helia 44 is 24,000.

In February in the Grenadines, wind will be in ample supply and my preference would be for the heavier vessel. Given your route, unless you decide to go from Mayreau to Bequia for some reason, you will be off the wind the entire time. If sailing the VI in the summer time, my preference would be for the FP.