I also have sleep apnea. My pulmonary doc wrote in my clearance that I had to have the CPAP machine in recovery room. Seems the anethesia lowers your breathing rate. I too was told by the bariatric team to bring mask & calibration settings the day of surgery.
As for masks, I am finally happy with the nasal canula style gear.
I will be banded monday 11/5.
Good luck to you