Hello, my name is Chris im 27yrs old from the chicagoland area, im new to this aquarium stuff...i built a nice wood stand for my 150gallon tank that was given to me from my dad he wanted a bigger salt water tank so he bought a way bigger tank, he gave me the 150g tank and (2) Marineland Magnum 350 pumps and a Aqueon 300w Aquarium heater, and the lighting that came with the 150g tank when he bought it. he sold all the rest of his stuff i was wondering what else i need to get the tank up and running i can't afford to do a salt water tank so i was wondering should i do fresh water or do brackish....not sure what i will need as i am new so i would like to do things right im looking for exotic fish dont know what i can get from a fresh water tank like that would be interesting maybe some aggressive fish etc. however i dont want them to fight and kill each other just looking for something that will be kewl/enjoyable....i was told brackish do tend to have a better selection of fish then normal fresh water, i would love any and all help so that i can possibly get my tank up and running if you have anymore questions feel free to ask and ill do my best to describe 

*type of fish i was hoping to get out of a fresh water or brackish depending on how much more it would cost to have brackish water set up.

Fresh water: cichlids and or waterever other fish can be kept in the same tank without them going crazy on eachother.
Brackish water: sharks/rays/trigger fish etc.....