MS SQL server sizing and information

I'm trying to get iniformation to my SQL DBA about what to expect when running OpManager with a back end DB on his SQL cluster. He had a few questions that I'm having trouble finding answers to...

1. How much storage is expected to be used by the back end database on a per monitored device basis?

2. Does the central server and probe(s) know how to communicate to a mirrored cluster? Does is it aware of how to talk to the cluster especially when the cluster is in a failed over state? Is that dependent on the OS I run opmanager under?

3. Do the probes and central server all talk to the same database instance?

4. Is there a guide somewhere that shows more information about the DB and questions like these?

Thanks,

Mike