I have this pack and plan to use with the predator stand and my helium sticks.
For those who haven't seen, it's a backpack shoulder strap system, but a large fanny-pack is all that's connected (low, like belt level on your back). The top of the fanny pack unzips and has another bag that can clip up on the shoulder straps and look like a full regular backpack.
http://www.alpsoutdoorz.com/products/packs/hunting-packs/pathfinder
I'm thinking I'll keep the top-pack folded down into the bottom part, and use paracord or something to tie buckles compatible with the shoulder harness onto the predator platform and/or a fleece wrap for attaching the helium sticks.