Chip,
The following link has some information on the cage culture of hybrid striped bass.
http://www.mdsg.umd.edu/Extension/finfish/FF3.html If they are anything like largemouths I've had great success putting them in large cages at low densities to grow them out over the summer to get them up to size to not become expensive fish food once they are liberated into the pond proper. Aeration near the cage to keep some moving water going through the cage and keeping your cage mesh clean of algae is a major plus.
I haven't messed with hybrids striped bass personally as I don't have a market for them but hope this information helps.
