The best in town
Manhattan Aquarium Company is the best, most knowledgeable Pet store in the city. They have friendly and helpful staff. Their fish tanks the the best kept I've seen.
These guys will help you all the way to almost planting the stuff for you. Ask them anything and they can answer. Great feel on landscaping just tell them what you want and they will get you what you need. They know there stuff. They go the extra mile to make sure you get what your looking for.