Lots of good advice in these posts, especially in Cubswin's and RedRiver's initial analyses of getting and using HH points. While there are all sorts of arguments about whether HH or SPG programs are better overall, I agree that HH serves the OP's needs better.

A few additional thoughts, based partly on my and my wife's having been to both of the Hilton French Polynesia properties and one of the Maldives ones (Waldorf-Astoria's Beach House Maldives) on points (though upgrading with $$ to the OWBs at the two FP hotels) in recent years.

1. All three are variations on paradise, especially if you stay in an OWB there. In fact, the OWB is such a special kind of experience that it is a big part of what makes these destinations special.
2. I don't know if complimentary breakfasts are possible for SPG elites at the St. Regis BB. In contrast, HH Golds and Diamonds have access to great spreads in both FP properties. (Only Diamonds have this at the W-A BHM.)
3. While it's true that the BB Hilton is even nicer than the Moorea one and that the BB scenery even more dramatic than Moorea's, there are advantages to Moorea in terms of more to do, Moorea not being as dominated by tourism, the Moorea Hilton having a fun little drinks/crepe bar perched over the ocean, and it being cheaper (at least in our experience) to upgrade to the OWB there than at BB. Plus, as Cubswin pointed out, if money is a factor you tack on almost $500 RT per person to fly to BB as opposed to the cheap ferry ride to Moorea. Finally, while both hotels and islands are expensive, the prices at BB are even more so.
4. Of the three HH hotels I mentioned, our favorite has been the W-A BHM because the room, deck and service are the best, even if the scenery is nowhere near as dramatic as FP. What's also great about it is that the OWB at the BHM is the standard room--you don't pay extra to upgrade to it--and its deck has a small (7' x 4'?) infinity plunge pool on it. OTOH, the Maldives is tougher and a much longer trip to get to (from the USA) than FP is, and the BHM costs even more points than the FP properties during its high season.
5. As someone pointed out upthread, getting to the Hilton properties even after you fly into Male, the Maldive's capital, is expensive. I've forgotten the exact prices, but the BHM costs about $450 RT per person for a combination of speedboat and plane, and about $650 if you just go by plane. The other, very popular HH property there, the Conrad Maldives, is closer to Male, but even it costs about $450 per person to fly there from Male.
6. Having said all this, I return to an earlier point: All three HH properties are variations on paradise.