Aeroponic pump question

Im making a pvc aeroponic setup and am getting mixed responses to the pump i should use. My setup will be a 10 site system with a total of 12 360 degree sprayers.

I have 2 250 gph pumps from my old setup and supposively they're not powerful enough. I was looking into something between 650-800 gph but seems like thats overkill. The 12 sprayers are the only water supply so based on that info what size is best? Or can i get away with the 250 gph pumps i have

any help is appreciated

I recently stumbled on this but not sure about it yet, seems interesting:

http://multiponics.com/2011/12/03/introducing-the-most-advanced-aeroponics-system-available/

...it looks pretty legit. You would likely need to add a cycle timer to prevent overwatering.