New reef check list and questions. Thanks in advance.

In the same boat.

I acquired a 55g with some equipment and am ready to set up as a marine tank. This is my first salt water tank. I have been looking for information towards a successful setup. Equipment wise, here's what i know and am prepared to tackle:

1) I am ready to start setting up a sump w/ a 20gal long tank and few acrylic dividers and some filter media. In it I will place an Emperor 400 power filter I already have and my heater. I will also be investing in a skinner that will go in this sump as well.

2) Main tank will have an overflow leading to the sump, and 2 powerheads on either side. I have a UGF but I doubt I will be using it unless already having the equipment makes it a must use? Live sand on the bottom and liverock in the tank. No fish for a couple of months.

3) Lighting, i think, is my current weakness. If im wrong or im missing something else let me know right away. I have single floresent bulbs now. What are my true options? I was looking at the LFS at the Hagen Glo T5 HO Lighting System - Double - 48. This is what im leaning towards as my low cost solution. Is there a DIY solution i should look at?

4) Water source is an issue for me. For the set up, im getting R/O water from the LFS. What about after the setup, like water changes. WHat is my best solution for this?

Any help will be greatly appreciated.

Thank you.