I may be way out in left field on this, so take it for what it's worth. I did own a G4 briefly; it was just way too big for the load I was carrying. I do still use a Granite Gear Virga frameless pack, and developed a trick for making it act like it has stays - maybe it would work with the G4, too.
Have you ever wanted a camp chair? I started using one several years ago; I find I sleep better if I can rest my back while sitting around. But, I found it hard to justify the half pound or more they weighed.
Then came my Virga - and the chair kit became a necessary part of the pack: I would leave my pad (a Prolite 4 short, though I suppose any pad that fit its chair would work) in the chair, deflated, and fold the chair in half across the middle. This put two stays side-by-side on each side. I then rolled the sides of the chair in toward the center, until the pad was the width of my back panel. I then slid this down the back of the Virga, locking it in place with the sleeping bag, and packed in the rest of my gear. Then I opened the valve to slightly inflate the pad to give it a little stiffness and thickness, for comfort. I found the resulting pack rode just about like an internal frame, and the chair stays became the pack stays.
It seems like this might work even better with the G4, since they'd have the pocket to hold them in place. Just make sure you put the rolled chair/pad in with the stays on the side toward the pack.
I'm even happier using that system now: my Thermarest Compack chair kit and NeoAir 66" chair kit together weigh only 18 ounces, saving me 3/4 pound over the old Trekker/Prolite combination.
I'm assuming the same idea might even work without a chair kit, using a closed cell pad and your tent pole (assuming you use something like the TT Rainbow), with the tent pole inside the pad, in the center. (If you had two poles, you could run them up either side.
Not sure if this is really what you're looking for, but just thought I'd toss it in for whatever it's worth.
Edited by Glenn (04/30/10 08:42 AM)