Before actually investing in anything living in your tank, I would strongly recommend that you buy & read 'The New Marine Aquarium' by Michael S. Paletta
, it covers nearly all of the basic questions, cost concerns, and gives solid advice on what to consider before and after buying..
I'm about half way through it already and have a MUCH better grasp on what I can and cannot do with my system. Gives you a check list of things to buy and even aquascaping advice.. congrats about wanting to join the SW
I can't wait to hook mine up!