Hi Rollin,
Like you I'm a lurker here because of the excellent discussion that go on here. Don't have to filter as much "opinion" as other places. I have spent the last 2 years working up my gear and skills. Like I you think that Cave Diving could be something I'd like to do in the future. As a relative new diver here are some opinions based on my experience buying gear.
1. Wait to buy your gear until you've done your course. Even wait to get a few dives before buying gear. Just in case it's not what you want to do and you change your mind.
2. When buying gear feel free to support your local dive shop but don't be scared of shopping else where. Dive Shops usually prefer to align with a certain brand, and may try to sell you gear based on that. Do whats good for you. I'm lucky (?) I only have online options so I don't have sales people pushing me anywhere.
3. As you have already done here, pick peoples brains here for gear suggestions, if/when you go the tech path, pick your instructors brains too!
4. I initially bought a BC with a wing, in hindsight wish I'd discovered BP & W before I did this. But hey like kids at Christmas we all get excited, and rush into things!
5. I agree with the DSS BP&W if I could have afforded it I would have gone that path, but due to limited finances I didn't. After research and chats with my instructor I considered DSS, Hollis, DiveRite Transplate, HOG, Halcyon, Aqua Mundo and a couple others. Prices are all similar (DSS is more expensive but your paying for service and quality). I'm 6 ft, 180 lbs, I ended up going with my second choice (after DSS) a Hollis setup 25lb Single wing, and a 45 lb double, my research, shop help and my instructor said it would be more than enough for what I want to do. If you go DSS Tobin sort you out.
Gear wise do some research on prices etc (try Dive Gear Express to check out prices, whether you shop there or not it's great website). From what I see most dedicated Tech divers seem to collect lots of gear over time
so I'm sure I'll get to use DSS yet!
Think about whether you'll be traveling with gear. This is a consideration for BP material ie DSS Kydex Hybrid, Aluminum or Stainless Steel.
6.If you buy a BP&W you will probably get some form of pockets (BC's have pockets, BP&W usually don't) see the Hogarthian section for a thread on this Consider getting a single tank adaptor (possibly), and I would look at getting a Hogarthian harness, forget all the harnesses with plastic clips and do dad's. Personal opinion but I think a lot of people here would agree. See the discussion above about entanglement, streamline etc. If you seriously see your self going down the tech path, definite consideration.
Assuming you buy gear before your course, definitely consider a couple other points
7. Think about fin choices Scuba Pro Jetfins, Hollis F1's etc. You might avoid buying twice like I have.
8. Consider regulators, if your going to get a BP&W you'll probably end up with reg's to. Do some research, a lot of the tech community prefer specific set ups and regulator sets. Again will save buying twice.
Sorry this is a little more than a BP&W discussion.
I will add here I am relatively new here and yet to get in a cavern much less a cave. BUT I have walked your path already in preparation for doing so. I have picked brains here and researched SB and other forums. You've done well just asking the question. Hope my experience and thoughts help.
Good luck & Merry Christmas