Heyyy... somebody should've dropped me an e-mail.
There are 2 "good" ways to attach pockets on to an Xtreme. Both use plain old wetsuit cement.
First off, run down to your local dive shop & pick up a fresh can of wetsuit cement. "Seal Cement" by Mcnett, and the cements by Global & Trident are all good brands. Then hit your hardware store & pick up a small can of toluene. This is the same stuff that's called "wetsuit cement thinner" in tiny cans that sells for several times the price.
Figure out where you want your pocket & mark an outline of the area. Wipe with a light coat of thinner. Wipe the backside of the pocket with thinner as well, and apply 2 coats of cement to both surfaces, allowing to dry tack free (just dry to the touch).
Carefuly align & plunk the pocket down. Either roll with a "special tool" or smack it with a rubber mallet to get things to bond securely.
The second technique is nearly identical except you roughen up the areas to be glued with 60 grit sandpaper after wiping w/thinner. A second wipe w/thinner is then in order before applying the glue.
Roughing up will allow the cement to grab on so tight there's no chance of even intentionally stripping it off if you ever want to replace the pocket sometime down the road.
Viking has good pockets but they're way expensive.
Northern Diver has some that are pretty good & you can order direct, just ask for the bellows pocket. Cargo pockets have a zipper. I have a heap of those things sitting here, (they gave me the wrong ones).
ND's "weight & trim harness" has 2 removable bellows pockets on it. When you consider that you're getting both a weight harness AND 2 pockets, it's a heck of a deal.
Check 'em all out at:
http://ndiver.com