repotting a divided Bulbophyllum lobbii

[nutgirl]

I need to pick the OB brains.

I divided a potbound, root-rotted, overwatered plant.
I'm left with a decent piece with 6 bulbs and several single bulbs with roots.

I would like to put the larger division into a basket. It is such a rambler.
My conditions are hot/dry in summer and although it will be watered daily it will also dry out quickly.
Can I used a fairly large (6 - 8") basket and let it grow into it?
What kind of medium do others use? I currently use lava rock with my Vandas in baskets but I don't know if that would be damp enough for the Bulbo. The Bulbo roots are much finer.
I can supplement with sphag or coir.

Would a small bark mix work for the single pseudobulbs?

Help
Maureen