Im now in the market for a BCD, but suffer from a bad back from time to time so looking for somthing with good protection and support.
From your post, I interpret your 'bad back' to be disc-related. Therefore, I do not believe that padding is an issue. Rather, what configuration minimizes the compression on the disc spaces (and flexing of the lower back when you have a spasm), and provides the most stable platform, primarily on land, is the concern. (If I have misunderstood, most of my subsequent commentary can be disregarded).
I had a lumbar laminectomy years ago, and still have an ocassional flare-up and spasm. So, to paraphrase a well-known - to some, notorious - politician, 'I feel your pain'. I can share what works for me. Your question involves several factors: 1) what BCDs are sizeable (and what size would be optimal for your physique), 2) whether weight-integrated BCDs are advantageous, and 3) what tank configuration would be optimal.
I started with a Zeagle Ranger, because it is modular and can be 'fitted' to a certain extent, and I would recommend it as a possibility. You can get a vest size to accomodate a trim waist and a shoulder size to accomodate your height. It is a very comfortable BCD, on land and in the water. The downsides to a Ranger are that it 1) has more lift in the standard bladder - 44 lbs - than you need for single tank diving, and 2) has a bit of padding which makes it positively bouyant, and therefore adds to your weight requirement, which is not what you want. That is a problem with many BCDs, though, and is not necessarily unique to the Ranger. But, most of the Zeagle recreational BCDs, specifically those with a more appropriate single tank wing size (e.g. the Scout and the Stiletto) are 'sizeable'. If you have a LDS that carries the Zeagle line, you can easily try on a unit with what the sizing chart would suggest you would need (probably, a 'Small' vest and a 'XL' (possibly just a L) shoulder unit. I am certain that there are other manufacturer lines with 'sizeable' BCDs as well, I just happen to be familiar with Zeagle.
I also like the weight-integration technology in the Zeagle line, and find it to be secure. The only time I had trouble with weights coming out at the wrong time is when I forgot to zip a weight pocket once, and went inverted to a good view of a wreck. And, I got a good view - of the wreck disappearing below me as I was ascending to the surface, while half of my weights were descending to the bottom.
Personally, I do not find a weight-integrated BCD to be necessarily 'back friendly', but that may just be me. I prefer a weight belt, it works better for me, but again that is a personal preference.
mike1010:
Another option to consider is a weight system like the DUI weight and trim harness, this distributes the weight between your shoulders and hips, weight integrated bc's are nice and all but lifting a leaden bc to swap tanks or just move around is pretty hard on the back imo.
A good suggestion. I have a DUI unit, and used it when I was diving my drysuit with the Ranger and a single tank, and needed quite a bit of weight. It is worth a try. I don't use mine anymore - as I said, I prefer a weight belt, and I dive doubles and a SS backplate much of the time anyway.
mike1010:
i switch between a bp/w and transpac (during classes).
At the risk of inciting the BP/W nay-sayers, I would also recommend you at least consider a backplate and wing. If your back issue is disc-related, the amount of padding on a BCD isn't relevant. The low back pain is from nerve root compression and associated spasm, NOT from the weight of the BCD pressing on your lower back. A BP is a simple, very 'sizeable' rig, and provides good stability in the water (and out, for that matter).
mike1010:
the transpac has all the padding and support you could ask for and is able to change to a side mount system if you choose to go that way (I've heard this is ideal for techies with back issues)
True, although I recommend taking the padding (shoulder pads and lumbar pad) off the Transpac to lower your total weight requirement. While I hesitate to appear to be recommending a sidemount rig to a new diver, this may be an option in the not too distant future, if you back issues are continuing. You can dive two sidemounted AL40s, get the same gas you would have with a back-mounted AL80, and it will take some of the stress off your back. This is a more expensive option - two tanks, two regs, etc. - but sidemount diving has moved from the realm of purely 'technical' diving and caves to recreational diving. In that regard, a simple TransPac harness is worth considering - it allows backmount single tank diving as well as sidemount double tank diving (and even backmount double tank diving, which is not an issue here).
