buy much live rock as u can afford. It greatly helps in filtration. It is its own bacteria factory. Cruched coral will aid in ph control, you can go with the sand but especially if you go reef. If you go sugar fine, then your filter and pumps will be sucking it up constantly. I know this from years of experience with clogged filters and burned power heads. Olaso, speaking of power heads, try to get the clips that hang them on the sid eof the tank because the salt water will deteriorate them much faster than fresh watewr and you will come home one day to a power head laying in the substrate spraing the sand of coral all over the tank.
If you want the coraline to grow you will need strong lighting, power compacts are preferred. You will also get an algea bloom your first month or 2 but just let it run its coarse, obviously scraping the cyano bacteria off (buble looking algea).
Protein skimmer is not worth it unless you get one big enough. Before, people used to think that you dsont want one too big. But,. now the bigger the better. I have one on my 125 that is rated for a 400 gallon tank and my fish only tank looks like a reef with all the colors of coraline from a deep red to purple to a bright pink.
Also, I cannot stress enough! Filtration, filtration, filtration. A refugium is best but not neccesary.
Make sure the live rock is fully cured or you will have an amonia spike in no time. Google "FOWL" Fish only with live rock and you will have all kinds of info. Good luck, its great going salt. Oh and Instant Ocean salt is $29.00 at bigalsonline.com. Print that page and take it to Petsmart and they will sell it to you for that price instead of $60.00.