Welcome to FishTankForums!
It sounds like you have nearly everything you need. The first thing you will need to know if Corals are your goal is how to properly cycle your tank. Read the Cycling Your Saltwater Tank thread stickied at the top of the SW forum. The CO2 is not really going to benefit you too greatly as a standalone system, although it will if you incorporate it into a Calcium Reactor. See this link for more info:
Drs. Foster & Smith - Calcium Reactor
Its good to start right off with corals and leave fish out. More expensive true, but better for water quality since corals produce far less waste than fish do. It makes maintaining water quality easier. I am sure you are going to want to get a fish in there too - fine, but hold off for a while. Keeping fish in a reef makes maintaining the reef tank much more difficult.
As far as lights go you will want something in the ballpark of 4-8 watts per gallon. Metal Halides are
great for reefs. They produce intense lighting from a near-pinpoint area and also create a highly sought-after 'shimmering' effect in the tank as the surface of the water is stirred. Moon lights can help, but they are not a requirement. I would shop around for moon lights as some kits are outrageously expensive and you can get a fully automated moon-phase simulated light kit online for under $100. Don't waste big money on three little LEDs with an on/off switch just because they are stuck in a fixture.
Metal Halide lighting is risky if you have never dealt with it before. The bulbs get
extremely hot and will melt the skin off your finger if you touch it while its on. You must use caution when working on or around Halide lamps. The heat generated by these lamps will also raise the temperature in the tank and might make it necessary to get a chiller. There are ways to get around this but that is a topic for another thread.
Light intensive corals such as Acropora do best under Halide lighting, but most corals will do just as well under Power Compact, or HO T5 fluorescent lighting. The latter options offer sufficient lighting at much lower temperatures but they both lack the beautiful 'shimmering' effect of the Halide.
For your size tank, with the goal of 7-8 watts per gallon you would want to get a fixture that produces 525 watts or more. This should be a good start for your corals and you can always ramp it up later on.
Again I want to stress that you
need to let the tank fully cycle before you start putting corals in. Most corals are highly sensitive to nitrates and you will have a lot of nitrates in the tank until the cycle is complete. No amount of filtration is going to make up for this in the beginning. It would also benefit you greatly to consider a 4-6" sand bed in the tank.
Plan your plumbing well as tanks with outlets drilled at the bottom are prone to overflowing the sump during a power outage if you do not set it up right.
Come back with any questions you might have and we'll take care of you.
HTH,
Aaron
