Hi Helen the best site to buy anything is just nebulizers because they are very reliable. I purchased there two compressors- ombraA and pari trek with a battery. I use my ombra for everyday nebulizing using the green reusable aeroclipse or pari nebulizers ( you can sterilize all parts of these). Ombra A compressor is strong and has a good warranty. Just nebulizers ask for a prescription so a emailed my doctors office and asked them to fax a prescription to just nebulizers. If you call just nebulizers - and they do answer the calls, they will take your order though and wait for the prescription. Good luck. I can see that you are actively taking care of your business after the Mayo visit. I wonder if you asked them about the phage therapy. Have a peaceful day