Which mask is appropriate for a full beard?
There are a couple of mask options you could consider.
If you comfortably breathe through your nose at night, the AirFit P10 (nasal pillow) mask is a good option, as it sits underneath the nose and forms a seal inside the nostrils. Facial hair is unlikely to interfere with the use of this mask.
Another popular option for males with beards would be the AirTouch F20. It is a full face mask which is a good option if you breathe through your mouth. The AirTouch F20 has a memory foam cushion which stays in place more effectively than other full face masks that use silicon, thus making it appropriate for use by people with beards.