Hi and .....
A 100 gallon tank is a great start. I started SW
with a 125 reef ready tank. Reef Ready (RR) just means that the tank is pre-drilled for drain and return linesand has an overflow box (or two). It is meant to drain water to a sump (another smaller tank) that sits below the tank and return water back to the main via a pump.
I would buy individual pieces, mostly online and get the tank and stand locally. The big difference between a reef tank and a FO
is the light that is requitred. Temp and salinity are about the same, the SG
should be slightly higher (1.024 -1.026) for a reef tank.
There are many reef safe fish to choose from, and some questionable ones and some that are do not even think about it. For instance I still have a coral beauty angel that was my 3rd fish. I've had it for 5 years now and it still has not touched any coral. It may one day decide to try it and then it will end up in someone else's tank. I will enjoy it until that day arrives or it meets it's natural end.
Go to the articles
section and start reading:
Getting started thread
Cycle your tank
Start gathering a list of equipment, fish and corals you would like to keep. Post those as new threads and wait for the responses.
The best advice I ever recieved here was that "That nothing Good ever happens fast in a SW
aquarium". Take your time, read and ask. Be patient and you will have a tank to be proud of.
Best of luck!