I loved working with Kimberly of Pyronamix
http://www.pyronamix.com/ She has the fabulous Regalia as well as less expensive reconditioned medical concentrators. We chatted for a while on the phone about what I wanted to do with glass and about my torch and other torches that might be in my future. She definitely wanted to make sure that I was getting what I needed for my set-up. The concentrator arrived in less than a week after I ordered. I recommend her very highly!