FreeHeel... Forget the DR...it is a hell hole and there is no security. Grenada provides everything you need...good prices, good yards, a daily flight in from Puerto Rico and "relatively" secure from hurricanes.
Grenada Yacht Club, Spice Island Marine, Grenada Marine, Clarkes Court Bay are all possibilities for dockside or haulout/store facilities. Dockside...for example, is roughly $7-8 bucks a foot on a monthly basis and you may do better if you negotiate for a long term rate. Electric is metered and expensive in most places. Another option is to take a mooring ball in one of the southern Grenada harbours and hire a person to watch the boat. This is even less expensive and I've seen EXCELLENT care of boats by Grenadians who provide moorings/watch services.
Oh yeah...you might want to think about Chaguramas Trinidad as well though security there is sometimes not great. Check out www.boatersenterprise.com
for marina links there. No hurricanes ever there.