Eden,
There is certified Blue Mountain coffee that you can be assured is the real deal. You can pick that up in most any store. Prices will vary, so do shop around. The Hi Lo Grocery store always has a decent selection.
There are smaller vendors around the area, some of the more popular at Cafe Goa on the beach road, and Canoe that sells Conquering Lion Coffee on the West End.
I am sure others will suggest some of their favorites.
