Kevin,
I would look at setting up a VLAN strictly for the SAN traffic. After the creation of the VLAN I would look at configuring I would enable packet marking and then create you class and policies. I would also enfore policing on the switch to ensure that traffic prioitization is being met.
I do not know how you are doing you SAN replications, but you will want to be sensative to delay, especially if you are using syncronus backups.
This will be a process of fine tuning until you get to where the reserved bandwidth is just the right amount for you SAN traffic, You might want to put a burst on there if you expect days of high replication.
James
