1. It is good to budget out the cost of your aquarium. You should leave plenty of money to purchase quality filters, pumps, and heaters for your aquarium. Your big aquarium is going to do you no good if you do not have the proper equipment to keep it going.
2. It is generally recommended to use natural gravel for the aquarium. Colored gravel can be used, as long as it is professionally made, certain cheaply made color gravels can be toxic to fish in your aquarium.
3. Purchasing fish that feed off of algae is a good plan to take care of an algae problem in your aquarium. You could also try cutting back the amount of lighting in the aquarium or get an algae treatment chemical to take care of any algae problems.