What is the best mount for a spider orchid?

[twinkie]

Someone gifted me a white spider orchid, no idea the name of it. It has 3 fleshy plump leaves about 6-7" long and the owner said she had it growing on a tree in Florida. Well, I live in the cold Pacific Northwest and grow indoors, so I put it in a pot with Cattleya mix and sphagnum moss but feel it's not quite happy....no signs of wilt or odd leaf color, but I sense it's not quite right in that pot though getting plenty of light. Would wiring it to a tree fern slab with a large pocket of moss work? I don't know how big the root system gets so what would be the best size slab? I've searched online but haven't gotten any real sense of how spider orchids grow root wise, and on mounts. I was also thinking to use a fluffy knitting yarn instead of fish wire - advisable? I've never grown mounted, and plan to put this one hanging where it gets dappled Southern exposure.
Thank you for any suggestions!