1.RESEARCH! RESEARCH! RESEARCH!
2. Test kits. Ammonia, nitrite, nitrate and PH are absolutely essential. calcium and alkalinity will be needed if you start to have PH problems or you want to keep corals.
3. A powerhead or two, SW tanks, should have/need a LOT of water motion, I would aim for atleast 10x circualation per hour, although 20-40x per hour would not be overdoing it. It's not only for the oxygenation benifit, but many bad algaes wich could/would drive you away from the hobby will not grow in areas with elevated flow.
4. An actinic light tube for the hood would be highly preffered, for asthetic reasons.
5. A timer for the lights would also be highly preffered.
And a few points I should mention:
It's highly recomended that you use your live and base rock (or just completely live rock) as a filter, as any other filter, escept for sandbeds, only deals with ammonia and nitrite, while live rock deals with ammonia, nitrite and nitrate. An added plus is the fact that should the power go out, all your bacteria is still in contact with the tank water.
Becuase of the above reasons, don't put media in the filter, or better yet, don't use the filter at all and use powerheads exclusively for your circulation.
You also didn't mention a heater.
You don't completely need "sw aproved sand", play sand or pool filter sand will work just fine.
Remember to mature the tank, not just cycle it, as marine tanks have a lot more things that have to be in place before fish will live happy in the tank. In your size tank, I would wait atleast 2 months after setting the tank up before adding any life to it, except maybe some cleaners after the cycle completes, to make sure the water remains stable and get a "feel" of how SW and your individual tank works.
