Live rock and live sand are pretty much a must. A lot of people buy argonite sand from home depot to cut back on live sand cost. Live rock can also be shortcutted by buying 50% live rock/base rock. Most people recommend 1.5#'s of live rock per gallon of water in tank. Live sand ranges from 2" sand bed to 4-6". There are calculators on this site for the sand amount needed I know. If you don't know how many gallons your tank is, there's a calculator for that. Live rock can be gotten from LFS
and a lot of people recommend liverock.com
Also get a decent protein skimmer. I don't have a tank as large as yours so I will let other people recommend one for you.
Powerheads are needed for water circulation. Get at least 2 if not 3 or 4 for that size tank where their combined flowrates = 10-20 X the size of your aquarium an hour.
Heaters will be needed. I recommend 2 because it gives you failover if one fails, the other can compensate for it not working.
If you want corals, good lighting. Either PC
Test kits for ammonia, nitrite, nitrate, phosphate, and ph
Avoid using crushed coral and any instant cycle products (BioSpira)
Also, have a credit card with a nice credit limit and lot's of patience.
And last but not least, a smaller aquarium to use as a quarantine tank.
Good luck. Read around on the forums and plan it out. You can get the rock and sand in the tank with water and spend the next few weeks studying up while the tank cycles.
Oh, welcome to AA.