Me recently four park stereo using a card of MOTU, the VRS supports up to 32 channels, Motu doesn't have a card of that capacity, m'as however if you combine several cards of a mark you can achieve it, revise you the list of marks in the p'agina of VRS and it revises each an until you find one that allows several cards in a single PC.
Sincerely
Walter Galvis