Finally got my setup the way I want it. I used two tall black-coated shelves from Lowes, which have lots of grids for hanging mounted plants. I also hung green hardware cloth down the left hand side for the mounties. (I did have to swap out the first shelves which were bare chrome, as they started rusting.) Each shelf is covered with Plant-Pro humidity trays from Tindara's. The lights are T5 four-bulb fixtures from HT Garden Supply.
Bottom two shelves (lower light) are Paphs, Angraecoids, and Phals on left; and Bulbos and Dendrochilums on right; with 21" between trays and lights. Top two shelves (higher light) are Catts, Encyclias, Tolumnias, Dendrobiums, Ascocentrums, etc., with 16" between shelves and lights. Plants are raised on stands or empty pots as needed to get them closer to the bulbs. Haven't decided whether to enclose the back and sides with a vinyl shower curtain to help raise humidity a bit.
Best thing about this setup is the tons of empty space I've now got! It's gonna be a
long winter until I can start ordering plants to fill in the holes.
Thanks for looking!