There is no way to get an atheros card on the gumstix. The CF bus is 8/16 bit wide and the atheros cards are all 32-bit Cardbus. The other option was to use the usb port on the verdex, but that won't work since the only available driver is NDISwrapper, which does not support any modes, but managed and ad-hoc.
The last possible solution is to put two gumstix together connected by an ethernet x-over cable and forward packets from the AP to the mesh node. The power consumption that way would be less than the meraki and we have direct control of what is turned on and can add storage to either one or both gumstix. I think it may actually be the best option at the time.