Kind of limited options from my experience there. Besides Budget there is a place in back behind of the crews in there at the marina. Its in the big steel shed. Dropped a few boat dollars there. Or should I say boat TTs.
I cant remember whether it was in Powerboats or IMS but there was a place when I was last there that stocked dozens of batteries. The guys at Electropics would know.
Check with Brian at Caribbean Marine Electrical in the Power Boats compound. If you need batteries now and are heading west, get them there...T105's are $235USD (!!!!) here in Colombia
Go and see Sheri or Fanny at Marine Warehouse at Tardieu, they are great and import stuff direct from US at very very good prices, deal with customs and do it all