Pony

[LKunze]

I agree with ChrisH on going with a 40 but nothing wrong with 30 if not doing tech diving in the future.  Also, I agree on rigging it like a stage clipping it on your left side D-rings.  One added plus to this method is that you can carry the tank down to the water and clip it on when you are in the water rather than on land. It's a little easier this way and you don't need to spend extra money and hassle with pony brackets etc.