If I were you, I'd take Fundies in single tank backmount. Sooner rather than later. Dive a hell of a lot. Then do drysuit and doubles, GUE primers on those are great, but it's not a huge deal. Any decent technical instructor can get you up to speed and proficient. The foundational skills you learned in Fundies will apply and you'll be able to easily adjust to diving dry and diving with doubles. Then dive a hell of a lot more.
Dive some more.
Dive again.
I'm really serious about this. You're a brand new diver. And based on your previous thread, you REALLY need to up your situational awareness and maturity before you even consider going deeper into your overhead training. And I totally get it, caves are freaking awesome. If I had gills I'd live there. But over-exuberance in the cave environment will kill you full dead in no time at all. You need a lot more experience just diving before you keep going. There's a reason that standards require logged dive minimums. I don't want to dissuade you from cave diving, I want to dissuade you from cave diving any time in the near future. Training is not a substitution for experience. Your training time is TINY compared to the actual time spent in-water outside of training. You need to gather this experience if you want to do this safely. A related example, there was a HUGE spike in rebreather-related deaths in the UK upon the introduction of the AP Inspiration. Why? Because divers who had lots of experience doing certain technical dives didn't take the time to gain experience on their units before doing the same level of dives they had been doing for years on open circuit. Again, these were incredibly experienced technical divers who simply got a new tool and didn't take the time to get the requisite experience after training, and they paid for it with their lives.
Once you've got the experience, find an instructor that you jive with. Whether it's GUE or with someone else. TDI, IANTD, NSS-CDS, and PSAI all have excellent cave programs. At this point in your diving career you don't know enough to make an informed decision on backmount vs. sidemount. You need to do a lot more diving before you can make an informed decision, as it will impact the instructor you choose and the type of training you'll end up doing.
You've got a long way to go, and slow and steady is going to keep you alive and enjoying all of the awesome caves out there. I strongly urge you to take a step back and really evaluate trying to roadmap everything right now with only a small handful of dives. You will be in a much better position to make an informed decision if you take the time to get experience first. Take Tom up on his offer and dive with him for a while.
Dive some more.
Dive again.
I'm really serious about this. You're a brand new diver. And based on your previous thread, you REALLY need to up your situational awareness and maturity before you even consider going deeper into your overhead training. And I totally get it, caves are freaking awesome. If I had gills I'd live there. But over-exuberance in the cave environment will kill you full dead in no time at all. You need a lot more experience just diving before you keep going. There's a reason that standards require logged dive minimums. I don't want to dissuade you from cave diving, I want to dissuade you from cave diving any time in the near future. Training is not a substitution for experience. Your training time is TINY compared to the actual time spent in-water outside of training. You need to gather this experience if you want to do this safely. A related example, there was a HUGE spike in rebreather-related deaths in the UK upon the introduction of the AP Inspiration. Why? Because divers who had lots of experience doing certain technical dives didn't take the time to gain experience on their units before doing the same level of dives they had been doing for years on open circuit. Again, these were incredibly experienced technical divers who simply got a new tool and didn't take the time to get the requisite experience after training, and they paid for it with their lives.
Once you've got the experience, find an instructor that you jive with. Whether it's GUE or with someone else. TDI, IANTD, NSS-CDS, and PSAI all have excellent cave programs. At this point in your diving career you don't know enough to make an informed decision on backmount vs. sidemount. You need to do a lot more diving before you can make an informed decision, as it will impact the instructor you choose and the type of training you'll end up doing.
You've got a long way to go, and slow and steady is going to keep you alive and enjoying all of the awesome caves out there. I strongly urge you to take a step back and really evaluate trying to roadmap everything right now with only a small handful of dives. You will be in a much better position to make an informed decision if you take the time to get experience first. Take Tom up on his offer and dive with him for a while.