broncobowsher
Contributor
As for the progression. Since a rebreather is a Nitrox machine that will be giving you Oxygen up to 100%, you really need to progress through Advanced Nitrox first. While it could be done in a rebreather class, it shouldn't. There is enough new stuff to learn in the first class that the Advanced Nitrox should be understood first. Advanced Nitrox is typically paired with Deco procedures. Since a rebreather will get you the deeper and longer dives you want, it will also be putting you into planned decompression. So again, get that out of the way first.
Next up is finding an instructor. There are a lot out there. My idea of a warning sign is a shop that only deals with one rebreather and has there in house instructor for that one model. Often they have not been on it very long. My run away moment when shopping was a local shop that had a model that I wanted more info on. The owner had his personal unit on display. Was commenting that he only needed a few more hours on it before he could qualify as an instructor on it. Did I really want to be his first student? I found another instructor who teaches on about 4 different rebreathers. That was better because he had been around the block a bunch of times. He had seen problems that are not "in the book" and knew taught that stuff.
Being as green of a (tech) diver as it sounds like you are, you are likely to get a 100' no deco card to start with. Not always, might get a little deeper, maybe a little deco. This will get you back into recreational diving but on a rebreather. Go dive. Do the local stuff. Get to know how to dive all over again. Learn to build and maintain the rebreather. Once you are decent at that, then another round of classes with some added Helium. This should get you to 200' and you will be spending hours of your life at 20' hanging on deco.
