[Myka]

1. Metal halide lighting if keeping SPS (I'm a die-hard MH fan) or T5s for LPS.
2. Over-sized good quality skimmer (really liking the SWC cones right now...have two of them).
3. A sump.
4. At least one controlled powerhead to make changeable flow patterns. I like the Tunzes, who doesn't?
5. A Tunze ATO, no other will do imo.
6. Good fans. I like the fan "banks" with 4 in a row. One set for the sump and one set to blow across the tank's water surface to blow the heat from the lights away. Good fans can remove 4-5 degrees and can usually avoid the need of a chiller if your house has central air conditioning. Chillers suck...they are expensive to buy and run, and they add a lot of heat to the room they are operating in. I'm using el cheapo Jebo fans right now and they are working very well.
7. Dosers or a calcium reactor. I prefer dosers.
8. Good quality test kits for calcium, alkalinity, and magnesium at least. I like Elos, and am interested to try out the Hanna Checkers.
9. Media reactor for GFO.
10. An efficient water change system that makes it easy so you will do it more consistently.