We provisioned with Grande Marche and I recommend it. One thing to consider is all the checking in and out -- you have Dutch and French St. Maarten/St. Martin, British Anguilla and French St. Barths. It can take a substantial amount of time, so be realistic about what you can do in a week.
When we went, we started in Oyster
Pond, went to Marigot, Road Bay Anguilla, Grande Case, St. Barths and Phillipsburg and back to Oyster
Pond. You cannot clear in or out of St. Martin at Marigot on a Sunday -- I learned the hard way. Also, clearing back in at Phillipsburg is a pain and no one seems to understand the rules; plus I was not all that impressed (though there are some good restaurants there).
, we found a nice spot at Ile Forchue and the diving
was generally better around St. Barth's than St. Martin. Leaving from Oyster Pond, there was a dive shop there where we got tanks
and weights. Don't know where DYC is.
So, I would suggest going to Grande Case (though you need to check in and out of Marigot -- take a cab) on the north side as a more interesting option than Marigot. Road Bay in Anguilla is pretty cool and they customs
people are very friendly (unlike the ones in Marigot). If you dive, you must overnight at Ile Forchue. There are no restaurants (sorry), but it is a great spot and worth the hassle of cooking
. St. Barth's has whatever you need and you need to go there to pay for the diving you did/will do.
I just returned from a week in the Spanish Virgins and I'm suffering from withdrawal already. Good luck and have a great time!