IME - its better to wait a month/however long it takes to save the extra $75.
You may want it set up NOW, but trust us on this one - once its all set up and you have a full stock list, you will wish you had a bigger tank. (I am stuck with a 42G and I wish I had a 75.... (75g can accomodate fish with a much larger appetite/bio load - eg, tangs, puffers, lions)
Another question - you mentioned originally you were after a coral beauty, what made you change your mind against it?
Also - check out the firefish goby - these guys have SO much personality (must be kept in 2 or more, or you will never see it)