Be sure to ask for a humidifier. I had a non invasive nasal mask that I like really well that had either the nasal pillows are a small nasal mask, but they discontinued it so I couldn't get another one. The next best thing is called a wisp. I believe it is a respironics product. It is a pain to take off and on, but it seals very well and not as invasive as a full mask. I tried the full masks, but had huge leaks with every one that I tried.
Hope you get a good fit because the mask is everything when it comes to cpap therapy. Another thing, is that they usually fit you sitting in a chair, but it is a totally different thing when you lay down with the mask on.
I would also highly recommend that you get some type of hose retainer. I run mine through a larger stretchy headband that is like a giant rubberband, then I hang this on a plant hanger that is mounted on the wall behind my headboard.
It keeps the weight of the hose from pulling at your mask and making it leak and the rubberband has enough flex in it to allow you to turn over, etc. without pulling at your mask.
Also, if you do get a humidifier, you will need to get/make a cover for your hose because the temperature difference in the room can cause rain out that will drip on your face and wake you up. Hope this is not TMI, but is just some of the things I learned the hard way.