And the drug shack should have Cuban boats docked at it, but that is another idea.
I like your thinking though :]
My idea for it :
Cocaine = Cuban sea-shack
Heroin = The big ship in the docks.
Weed = Can be grown in little haiti (1 is obtained each time a seed is planted)
Magic Mushrooms : Can be grown on a certain patch of Leaf Links, and takes 2x the time weed takes to grow (1 is obtained)
Ecstacy : Can be bought from several Drug stores. (Illegal)
Crystal Meth : Can be bought from the Drug Flat near Pole Position.
LSD : Can be bought at the Biker Bar downtown? (not sure about this one)
What do you think? :p