What you need is some kind of filtration that will export excess nutrient build up. There are many ways to do that, all of them can be very successful.
Liverock, Deep Sand Bed, Refugium with calurpa being trimmed, skimmers, mechanical filtrations, ect are all different methods of filtration.
I prefer using a pure of a biological filtration method as I can, thus I have liverock, dsb and refugium. That is it for me. But, you need to understand how it all works and the pros and cons to each method. Some methods are more labor intensive and hands on, some are less labor intensive but may have downfalls as well.
Most prefer skimmers, along with what I have to help with nutrient export. Some think skimmers can take out elements that are beneficial to your tank. I have never had a skimmer to say how well they work or not, but my tank has thrived without one for two and a half years strong.
So, my advice is that there are many methods. Do some searching on the forums and find out pros and cons to each method. Then design you setup around what will work best for you.
I know that was not much help.
For every thing else, you obviously need lights. I recommend getting the best you can afford. It sucks to have to upgrade your lights later, trust me. Lights will depend on what you want to keep as well. I.e. sps dominate, or lps and softies, clams ect. One bit of advice is to try to use the "zone" rule. That is, keep corals that are from the similar zone, so they all need the same type of light, water flow, nutrient levels ect. I did not, and it is a pain to keep corals with lots of various needs in one ecosystem.
A top-off system will be very useful at some point in time.
Just start slow and have patience. The more time you take, the less money you will waste on things you don't need, or have items die.
