The synergy generator is very good, but it is not a cold corona design.
I have used a cold corona generator as well, and the synergy performs just as well.
Never use air fed generators ever.
For injecting ozone you should use pure oxygen from a tank, but for saunas, insufflation, ozonating water, ozonating oil, or funneling, a good oxygen concentrator is fine. these will produce upwards of 90-95% pure oxygen. Oxygen concentrators are infinitely more convenient than refilling a heavy tank.