Wow. Seriously dude, slow down. You are going to have to revise your easter basket.
For the Firefish, you have to make sure you buy a mated pair, they potentially can kill each other.
Royal Grammas shouldn't cost you more than 20 dollars. I don't care what it is.
Being a fish ecologist (to a certain extent), I can tell you identifying the gender in a Royal Gramma can be difficult.
- Is the 55 Gallon Tank you have drilled? If it isn't you have to pay to have it drilled or get a Hang on Back Overflow in order to run a sump.
- You do NOT need 2 200 Watt Heaters. Just buy ONE 250 Watt heater and you are fine. Eheim Jager Heaters are fantastic and cost about $30.
-You need to buy a protein skimmer. Either a hang on back or a in sump (if you go this route). Look at the Aqua C Remora Skimmers w/ Maxijet pumps. This works well and can support your tank
-For an RODI unit check out Purewaterclub.com They have a 6 Stage RODI you can buy at a good price. Also Air,Water, and Ice (MR Vendor in Marketplace) has RODI units at a good price and stellar customer service.
-More importantly you are forgetting one big cost. Live Rock. This can be anywhere from 3-7.00 a pound depending on where you get it. For a tank your size you are going to need about 40-50 lbs.
-Then you have to think if you are going Barebottom on the tank (no sand) or sand bed. Sand should cost you about 50 dollars for 50 lbs. depending on what sand you get.
-You will also have to think about flow. You will need to buy powerheads. Koralia's or Maxijets perform well and are affordable.
-For Lights, it depends on what you are going to keep. If you are going to have soft corals. The least you can do is a Powercompact flourescent. If you want SPS you are going to need T5 to metal halide. It really depends. You have a 48" length tank, there are some for sale in the marketplace as well as online. This should run you about 200-250 dollars for powercompacts.