I have my Paphs in a mix of medium and (very)fine fir bark, and perlite. The very fine bark retains moisture quite well. I actually use the mix I make for cyms, just pulling out the biggest bark chips as they don't fit well in the small pots my paphs are in
Mine are currently in a mixture of fine/medium bark and medium CHC. Not sure it's completely right for them I would rather an finer CHC, but they seem happen enough.
I use a mixture of cocunut and fern chips, perlite and s/h. Pretty much all of my mixes come directly from RePotme.com where you can buy a mix that is premade or make your own combination according to your particular desire.
I grow mime in the finer bark and sponge rock mix and some are in Spagh. moss .
When I first started with them it was a disaster stayed to wet >>>rotted roots .
Received a tip from from a long time grower to layer the moss with pieces of non melting Styrofoam like an ice cream parfait .Works good ..