one thing with having two foam pads, my pack just has straps for one pad at the bottom of the pack, the straps aren't long enough to roll two pads together so I'd either have to piggy-back it, or find somewhere else to attach it. any suggestions? Later, I may try to attach some pics of the setup we have so far and the (admittedly crappy but usable for now) packs we are using.
Without seeing the specifics, my only thoughts are to ensure you roll the mats as tightly as possible and then to use cordage to rig up your own attachment method.