Hi again Carlos,
as I mentioned in your first thread, try the <<SEARCH >> button. There are several threads dealing with the Azimuth. Or just kick back on a quite eve and look through the archives. I spend several nights doing that, and plenty of questions were already answered. Then again, new ones popped up.
For more info on the Azi check out:
http://www.rebreather-azimuth.com/rebreather-engl.html
http://www.nobubblediving.com/azimuth.main.htm
As with any active-addition SCR (like the Drägers) you'll NEED a way to monitor your ppO2. Either with the addition of an Oxygauge (Dräger), a dive computer that uses the Dräger P-connector (VR3 or Explorer) or the Uwatec ZO2/Oxy2 combo with an adapter.
The can be infinitely set between 32% and 60% Nitrox. At 32% you will reach a ppO2 of 1.6 at 40 meters. The AF version can take two mixes, so with Nitrox, Trimix and the proper training you'll be able to go deeper if needed.
As with anybody else who is new to RBs I recommend you read Steve Barsky's "Simple Guide to Rebreathers" and Jeff Bozanic's "Mastering Rebreathers". Then have a look at the specs of different units, and manuals where available, and you'll have a pretty good idea of what they should be able to do.
As you don't post your location, I can't say what the supply situation is. Nor can anybody else. Here in L.A. it's pretty good.