I have the same model only mine is prescribed and (mostly) covered by insurance.I bought my own on FB Marketplace, a "like-new" Philips Dream-machine (or whatever its called).
Easy to use, program, etc...
You want a sleep study for a cpap as it’s designed to match your oxygen level needs
Now a apap is what you’d want as it’s not needed to setup your oxygen level it changes through out the night depending on your breathing
had a cpap for 4 years now would take a apap anyday far superior