Hi,
You can use mobile phones of course. I would use network boradcast to send trigger signal.
You will struggle (and need to be patient) to download the images over wifi. You need to make sure you do this in sequence not parallell as that will kill the wifi network. Keep in mind 100 x 8MP ~ 400MB, if you will use projection (which I would recommend) it means per scan 2x 400MB = 800 MB. If you want to auto mask with empty scan = 3x 400MB = 1.2GB per scan! so that will really take some time over wifi.
The most important thing to test is to see if you access point can deal with multicast to 100+ units. So make sure you have tigger syncronization.