A larger system would provide a bigger cushion form error that would wipe out your system... That is a decision you will have to make. You are going to need some salt (sold a LFS
), a heater,lights, hydrometer (measures salinity), thermometer, Filter, sand and live rock. Eventually you might need a sump, powerheads, and a protein skimmer. If you get enough live rock and live sand it will cycle your tank for you (this is how I cycled mine). Then it turns into a waiting game (3-4 weeks for a full cycle). This is truly the hardest part. Your fish store might tell you to cycle with a fish but many people here are adamant against this, including myself. It is cruel to your fish, they likely WILL die and it is a waste of money.
There are a few different ways to cycle a tank though. Some people will use a piece of shrimp or pure ammonia from the hardware store to get the nitrites and nitrates where they need to be. I've never cycled like this though.
Do you want to keep a FOWRL (fish only with live rock) or a Reef tank which includes soft and hard coral? If you eventually want to keep a reef tank you might want to get a higher quality light as the coral need them to flourish. A lot of people use metal hallides or t5's. I personally just ordered AquaticLife T5 HO 4-Lamp Light Fixtures w/ Lunar LEDs
for my 29 G setup.
That is all I can think of for now.
Welcome to the salt side. If you have any questions don't feel shy.