Do you have a canopy? If you want SPS I would buy a 250watt halide retro. One of our sponsors has them on there site for $159. If you want medium light then you can buy PC retro's from phil and shelly at coral beauty. If you don't have a canopy then you can buy the coralife PC fixtures from most of the stores such as blue seirra or SWC( Saltwater City). You could do Vho's but they would probably cost as much as a 20k 250 halide. for low light you could do 2-3 65watt pc's 2 will work for LPS and soft coral and 3- would work for some SPS and probably all LPS. Also you can look into T-5's. These are good lights but I haven't seen them at a good price unless you are a DIY person.
DO YOU HAVE A CANOPY? AND YOU MUST DECIDE WHAT IT IS THAT YOU WANT TO KEEP. WHAT DOES YOUR SYSTEM CONSIST OF? WHAT IS YOUR TANK SIZE? THE CHEAPEST ROUTE TO GO I WOULD SUGGEST IS A POWER COMPACT FOR A SMALL TANK OF A VHO SYSTEM FOR 3' LONG TANK AND ABOVE. DO YOU HAVE A SKIMMER? SHOOT ME AN EMAIL email@example.com AND MAY BE WE COULD WORK THIS OUT WHAT YOU HAVE AND WHAT YOU MIGHT NEED.
I had a 29, and a 44 gallon reef both kept under compact flour. lighting by Coralife. I kept in the 29 high up on the rock work, a dersa clam, and a bulb tip anemone. Plus many LPS corals. It is a great size starter tank. With moon lights built in it is 166$ with out moon lights it is 153$ The tank rim mounting legs are 9$ For the money it is a very good deal. I hope this helps you. Steve
Like Dave said, do you have a skimmer? What kind of filtration are you using. Tell us more about your system if you will. Steve
I call my 29 gal tank "my nano". You can check it out in my photo gallery. Is this what you want? I've got a 24" "Orbit Compact Fluorescent light fixture" with two 65 watt PC bulbs and two lunar lights. Works great! Paid 190.00 but I'm sure you could find it cheaper. Works great for what I have however, if you want acros or something else that requires stronger lighting you shouldn't use this. It all depends on what you want in your mini reef.
If you do have a canopy then you can screw the lights into the top. I have used the coralife fixture over a 29 and It was okay. I have also used halides and I went towards the SPS. mtndewman used to have a 29 with a 250 over it.