Good friggin lord...
If you are serious about doing this, you are on the right track by getting training.
Now SLOW down, you gotta walk before you can run. No matter how badass you think you are, you have to be serious about evaluating your own skill level, and experience level. You have to learn to recognize what problems you'll face in the overhead environment, which will take experience. You'll have to know how to alleviate those problems, which will take training. You have to do all this safely, which includes buying the right equipment. You really need to take other people's evaluations of you seriously, not just shrug them off.
It doesn't take much for Cavern class. You can do cavern with pretty much everything you have for OW diving. You'll ditch the snorkel, get a 7' hose, and a reel. Its not a bad idea to go ahead and get aquainted with this gear before the class.
Then take Cavern. Soak it all in. Then dive caverns, for AWHILE. It truly will do you some good.
Get out of the attitude of faster, farther, deeper, RIGHT NOW.
Then take Intro, and stick to Intro Cave diving for awhile. There are alot of caves out there with beginnings that you haven't seen yet. No need to get to the back, when you have so many beginnings to see yet! This is where you're gonna have to start really looking at different gear setups, as your OW rig isn't gonna be ideal.
Then worry about Apprentice and Full Cave certifications. Even then, progress slowly, all these certifications are just stages to progress your learning farther. Get ready to buy even more gear, doubles are a must, deco is gonna happen, redundancy will be key.