I started out with a 4' 4 lamp t8 (32 watt) fixture from Home Depot but found that while it would bloom phals, it just wasn't enough light. I have since purchased 4 High Output (54 watt) fixtures from 2 different vendors. These put out twice the lumens as the 32 watt fixture. Still not sure they will make my cattleyas bloom but time will tell. Also found a method of using one single, and one double 1" pulley (from Loews), and para-cord to create a method of hoisting the fixture up and down.
They are t5, and not t8. I bought 2 from htgsupply.com for about 149 each. I bought 2 from growershouse.com for about 110 each. htgsupply lets you choose 2 3500k and 2 5000k lamps with each fixture. At Growers House I bought both at the same time and chose one with 4 3500k and one with 4 5000k lamps then installed 2 of each lamp in each fixture.
I have exactly the same setup, and I *love* my lights. Not stoked about the electrical bill, but hey - I don't have to pay for a heater! And I knew what I was getting into.
I actually had to remove bulbs because my plants were getting too much light.