We are planning on running 2 spikes (y-cable'd together) to 2 valves, then have a system to make sure they run around the same, but still with the increased airflow.
Our system looks something like this:
http://img266.imageshack.us/img266/601/flowms7.jpg
... we ran a spike on each for some reason I don't know. Probably because our team thought it was illegal to run 2 off of one. ;P