buds:
Are all Oxycheq single tank (Standard) wings of the 30# variety all Dougnut Shape??
Yes
buds:
Are there any single (standard Oxycheqs) that are horse shoe shaped in the 30# flavor??
No ... but Deep Sea Supply makes a horseshoe shaped 30# wing that is an excellent performer. OMS also makes a horseshoe shaped 30# wing, but I have no personal experience with it.
buds:
And.. What importance does the shape play it the performance of the wing or is it just a carry over from Hosre Shoe shaped wings from double tanks?????
The "donut" vs "horseshoe" thing is a bit overblown on internet discussion boards. I've dived both, and while I think there are some minor advantages to the donut shape for singles wings, the overall "footprint" of the wing has far more impact on wing performance. Overall shape always involves tradeoffs.
For example, a wing with a narrow footprint will vent nicely, but with larger-diameter cylinders will tend to get "trapped" under the cylinder and won't inflate to its full capacity. A wing with a wide footprint will provide excellent stability when inflated, but will taco around the cylinder when partially deflated, and as you ascend the expanding air in the wing gets trapped, making it difficult to vent.
When people talk about one wing performing better than another, what they are really talking about has more to do with personal preference ... and how their particular rig trims out ... than it does with actual wing performance.
The most important factors are proper lift capacity and making sure that the overall shape of the wing is compatible with the size of the cylinder you plan to use with it.
... Bob (Grateful Diver)