I actually did the same thing this year for my orchids and other house plants for the winter. I had a four shelf wire unit with movable shelves that is aprox 4' wide and 16" deep and the unit is a little over 6' tall. It was originally used for storage and extra shelves in a back bedroom. I used the bottom of the top and the shelf below it, I could use the third shelf if I wanted to. I used two shop lights like you did and I used 1 cool and 1 warm in each fixture and the chain and hangers I used 'S' hooks to fasten them to the wire grid above them. I also used the plug bar but I added a timer so I didn't have to worry about turning them on and off. I used plain ole every day aluminum cookie sheets to put under the pot saucers so I could keep water under them to raise the humidity around them. It's worked out really great. I may add the third tier next year.
I think may people out there could use this kind of stuff as the one you would buy through a catalog are like 250.00.
