Can I ask a dumb ish question? I don't know much about Kydex except for that it is pricey. Are you recommending a wing with less lift because the Kydex plate is lighter than Aluminum?
Not a dumb-ish question at all. It's hard to know how much lift you will need; I suspect 20 lbs or less would sufficient based on what you've said, but it's only a guess. Most of the small single tank wings commonly available seem to be in the 30 lb range, and that's the reason I recommended that for the oxycheq. They do make a 17 lb wing which is really small, but when you hold the 30 lb next to it, there's not much difference. DSS makes a very nice 20 lb horseshoe wing called the LCD.
If you want to figure out exactly how much lift you need, you just need to figure out how negative your rig is without you in it, and you need to know the weight of your gas and the buoyancy of your suit. You need enough lift to A) float the rig without you in it, and B) compensate for the weight of the gas and wetsuit compression. That's it...and it's often less than you'd think. As an example, take your HP100, that's maybe 7lbs negative, add 5 for the regulator and other gear, that's 12. (This is with a neutral plate/wing/harness) So you need at least 12 lbs, say 15 to be on the safe side, to float the rig; that's without any lead on the harness. Any wing will do that. If your suit takes 15 lbs of lead to sink, and the gas weighs 7lbs, that's potentially 22lbs negative you could be at maximum depth with a full tank. So in that case you'd want at least 22 lbs lift, although its a little deceptive because probably your suit would not lose ALL its buoyancy at recreational depths, and you won't have a completely full tank by the time you got to real depth.
Then there's the issue of how wing companies measure and 'rate' their wings for lift capacity. Once the wing is on a tank, especially a donut wing, parts of it will not inflate fully, so possibly there's less available lift than the manufacturer claims if they measure it while the wing is fully inflated free-standing. There's no 'legal' standard for manufacturers' claims to accuracy in lift rating. You can measure it yourself easily by setting it up on a tank, filling it with water to capacity, dumping the water into a bucket, and calculating by volume or weight.
Then there's the issue of how high you would like to be able to float in the water while you're on the surface. There's no need to have your shoulders out of the water, but some people like it and if you want that, you need a slightly bigger wing. That's because some of the wing will be out of the water and so will not be contributing lift. The problem with bigger-than-necessary wings is that they are usually a little harder to vent and in general don't feel as nice to dive with, IMO. So it's a trade off. Experimentation is the only true way to find out what will work best for you. You RARELY hear experienced divers complaining that their wings are too small though; quite the opposite.
I don't think that kydex is significantly different than AL in terms of buoyancy. I think they're both more-or-less neutral. DSS uses kydex for other reasons; I think Tobin just prefers it; one reason is that AL definitely does interact with sea water and slowly corrodes. While that's true, remember that most other manufacturers have been successfully producing AL plates for years, and they make scuba tanks and boats out of the stuff.
The DSS rigs are integrated systems in which the plate and wing fasten together in an ingenious way which allows for almost instant removal of the wing; a nice touch for cleaning, storage, and travel. That's why IMO its better to buy DSS as a complete rig. Despite Tobin's rather blunt approach to posting on this forum, he has a stellar reputation for customer service that I am certain is entirely deserved.
The oxycheq wings are extremely well made and line up fine with either oxycheq or dive rite plates. Sometimes caveadventurers.com has excellent deals on those set ups. The newer style dive rite travel EXP also looks good to me, and I've always had a good experience with dive rite as a company. Not everyone else has.
Good luck, hope this helps you.
