Hi Diego
Stanhopeas are pretty flexible as far as mix goes. As long as it's free draining but holds some moisture for the roots. The parts you mention below should be ok.
Main point with stanhopeas is that they must be in a hanging basket lined with sphagnam moss, paper or tree bark which the spikes of the plant can penetrate.
You'll get the idea from these photos.
https://www.google.com.au/search?q=s...w=1235&bih=657
Enjoy the plant when it flowers. They are magnificant.
I grow several species and hybrid stanhopeas and they are all impressive in their own special way.
If you are interested please follow me on twitter at
www.twitter.com/onlineorchids. I update regularly and at this time of year much of what flowers are stanhopeas.
Cheers
John