[JesseK]

The Q&A seems to [url=http://forums.usfirst.org/showthread.php?t=16123]confirm that there is no restriction on quantity or type of storage tank. Just be sure to consider the engineering tradeoffs of actually having such a high volume of stored onboard, considering that technically the volume must be filled by the 1.03 cfm compressor even in the pits.

There are tradeoffs, they're just somewhat subtle.