You can probably find hot mustard powder in Barrio Chino, chipotles I've found canned (not very often, and not in a while) at Jumbo and some bigger Discos. Jerk seasoning spices I've never seen. Garlic salt used to be available but I haven't seen it in probably three years or more.
You can easily get basic spices here like crushed red peppers, garlic powder, oregano, paprika, dill, etc.
I make my own garlic salt. I have people bring down things like Old Bay and Lawry's season salt, steak rub, etc. I've made my own combinations of those things as well in a pinch.