So, I stayed out of this thread to see what direction it would take. I envisioned what would happen would be a 17 year old kid arguing with every post and fighting tooth and nail the whole way to explain why his ideas were right, despite 200+ years of diving experience here telling him differently.
But I guess the 17 year old OP has more common sense and wisdom than I did at 17. Hell most 12 year olds do.
Weekendwarrior didn't do any of that.
Kudos
At any rate, Weekendwarrior...
I get that you want to run after this with everything you have. A lot of cave divers have the same personality type. It's great that you have a passion for this sport and want to experience it all, but you HAVE to realize that this is a marathon, not a sprint. While there is easily 30-40k worth of dive gear in some CCR cave divers' garages, it didn't happen overnight. My first cave setup was bought on layaway. Hell, my second cave diving rig was bought on layaway. It's taken me nearly 20 years to have the gear I have. I swear to you, if you do this all overnight, you will be out of this sport in 2-3 years.
Cave and Tech diving is like the perfect beef brisket. You can't smoke the perfect brisket in 30 minutes. It may take 20 hours. If you get in a rush, the finished product sucks.
The secret to really enjoying 100% of what this sport has to offer is to take your time. Experience every part of it to the fullest. Once you've mastered everything at your level, move on to the next level. I know, it sounds stupid.
I'll give you another example.
When I was 18 I started buying sport bikes. I started with a Kawasaki EX500. It was the second from slowest Ninja you could buy. My mentor who sold it to me told me to take it slow. I didn't need to do every wheelie, burnout and trick I could get it to do the first week. I didn't need to see how fast it would go today. Of course, I was 18, so by the end of the week, there wasn't much I hadn't tried on that bike. Less than 6 months later I was bored with that bike, looking for something faster, cooler, handling better. I moved to a 1000 Ninja, double the cylinders, double the horsepower, and would wheelie in the first 4 gears, oh and I went from 120mph bike to a 150-160mph bike. I blew three of those up in the first year. Then the ZX-11 came out. I had to have one. It was the fastest bike ever made (until the hayabusa in 2001) I remember flying down the freeway at 140mph on one wheel. But by the time the Hayabusa (193 mph) came out, I was already bored. I had every fast bike you could buy from 1992 - 1999. I went fast, did burnouts, drag races, wheelies, blah blah blah, so what. It's all the same at this point. Today, I have absolutely no interest in having a motorcycle. I've already done everything there could be to do, there's nothing new to experience.
Scuba diving can be like that. PADI states that in the first 3 years after certification 98% of divers will quit diving. There are several factors that play into why that happens, but if you love this sport, let it be a life long passion. No an obsession that dwindles away in 3 or less years.
Now, on to some of your other comments...
I'd advise you to move away from the PADI path in your technical training. There are better options, seek them out and use them. Most cave divers are NOT using rebreathers. In fact when a new permit opened up last year at a very awesome 300' deep site, of the 20 people on the permit, only two divers showed up with CCR. I was one of them. Rebreathers are growing, but they are not the majority in cave diving yet. There are many reasons for this, but the two biggest are probably cost and simplicity of Open Circuit. If you don't think you can enjoy diving on open circuit, then I promise this hobby is not for you. Crap gear, awesome gear, OC, CCR, if you are not in awe of the underwater world, then don't waste your cash any further, you'll outgrow scuba soon. Hey it's not for everyone. While I'd rather be on a rebreather, I find the cave just as beautiful and amazing on OC as I do CCR.
My advice... take it slow. Enjoy it. Don't rush, certainly don't try to buy a rebreather now, even a good one. And oh, by the way, the one you are looking at is NOT the one of several you should buy. Save up, get great instruction. Buy dive gear that makes sense based on what you'll need in the future (buying twice because you purchased wrong sucks).
If you need any help, let me know.