I have lots of potted trees and plants, I make my own "mix", I buy that regular dirt you can find at local nurseries, usually around 80 pesos for about 100lb bag, then I add a small bag of shredded coconut coir, this is cheap, about 40 pesos. from Ferreteria Americana, has available "sunshine mix" I use the #4, has more perlite in it these run around 120 pesos. and finally a bag of worm castings also 100-120 pesos, I mix this up real good, and it makes a pretty good potting soil.
Superplants has pre mixed stuff available also, they are located on Autopista Duarte, around Villa Mella, best time to go is on Saturday, you can find them, they are past the Rica outlet on your left if your comming from S.D. you'll see a lot of Bamboo growing. but that is a drive, and what you spend in fuel you can make your own, but if your passing by superplants anyway , take advantage, they also have lots and i mean lots of plants for sale, and at pretty good prices.
perlite is available on its own, but is expensive, and usually only comes in humongous size bags.
As for Basil, I have Holy Basil, growing very well, peppermint also does ok. I have Lemon balm, also, medicinal herbs, Andrographis ( from india ) is naturalized in my back yard, Ashwagandha is prone to white flies and mold,
experimenting this year with Epazote , Mexican tarragon, Klipp Dagga, so far all doing well, so there is lots of stuff that will grow in the heat down here, i have had bad luck with tomatoes though, I brought back some Florida Everglades tomato seeds, and have a few plants sprouted, hopefully Ill be successful with these, supposedly they taste great, and can take disease, heat and humidity.
the only insecticide I use is Neem oil, which is available cheap locally, I try to stay as chemical free as possible.