These are the bags I use from Kingpin. They seem to have enough room, but are pretty thick, so I may have to get thinner ones to feel the give knob. Anyway, I found it helpful to put a rubberband towards the rca post to keep the bag bunched up front. Just and idea for what it's worth.

On another note, did my first piece with the Edge... and I freakin love it! I know I still have a lot to learn about it, but already worth every penny