Hello everyone again. As I wrote earlier, thanks to you, I was able to assemble SCBA and that's it required for method N2. I did not have a large budget, so all the components diligently searched on Ebay (you can use any site with ads). It was difficult, but the result exceeded all my expectations. I was able to find a seller who sold me fully serviceable Drager (DrƤger) kit which is fully assembled by the factory. My kit turns on the reducer (breathing apparatus, I don't know how it's called correctly, on the pulmonary machine it supplies a pressure of 7.5 bar), a lung machine with positive pressure (this important, Drager with a blue button works on negative pressure), a pressure gauge with warning whistle that goes off at 50 bars. The Drager mask is new. Want pay attention, I was surprised at how comfortable it sits on the face. The mask is very comfortable. Tank 5 liters 150 bar, which is more than enough for this implementation. Adapter G 5/8 (mom) for my tank (it was also not easy to find). The cost of all my accessories does not exceed $250. I have almost all the components, except for the G 5/8 adapter and masks are not new, but in good condition and, what is important, from reliable and high-quality manufacturers.
Tank 5 liter 150 bar 50$ + nitrogen filling 10$
New mask 80$ (I also bought on Ebay probably cheaper than from the official representative)
Drager reducer, pressure gauge, lung machine 100$
Adapter from G 5/8 Drager to my tank $10
The length of the hose from the lung machine to the reducer is approximately 1.5 meters.
The main thing is to choose the kit that maintains positive pressure in mask is very important. With a negative breath, it is harder to do.
Sorry for my English, I use google translate.
@GasMonkey special thanks to you for your help! Thank you for pointing me in the right direction.