Setting up a lionfish tank

Im currently planning on setting up my 50 gallon tank again. I need recommendations for specific items but as of now, but I plan on getting an Aqua Clear Fluval Power Filter. Other than that I know i absolutely need to buy dechlorinator, rocks, sand, salt and a hydrometer, as well as a thermometer and heater.

The fish I plan getting for this tank is a Fuzzy Dwarf Lionfish to start, and for clean up crew I was thinking about getting a Brittle Star.

Please feel free to leave suggestions as to what else i should get to put in my tank