This is where to do your research. Good tip m...
Resmed is the big name in the industry. My machine is not Resmed, my mask's are, which I buy from Amazon (could be cpap.com supplier).
I also found the hose too short, I am single and toss and turn all over, so I bought a second hose and connect the two. I also buy extra hoses because I rip them to shreds when I am high and the hose lands on my face, I freak out.
As mention The cpac
The sleep test should have fine tuned the pressure to a single value, not 5-15. There was a huge jump(difference) for me when I went from 7 to 10 (after sleep study).
That pressure is an Rx as you mentioned, I believe the pressure and settings are locked, my units always were.
The vendor will handle all the paperwork for OHIP and also will show you how to velcro the strap around your head to justify they have given you medical instruction.
Humidifier, is also (as mentioned by "/u Meaning") too hot for me, I don't use it, the hose is actually heated. The humidifier and hose must be cleaned every night else you risk serious bacterial growth.