Questions related to Multiple Sites module in SQF

Good afternoon- 

I am the SQF Practitioner for a warehouse/distribution company in Wisconsin. We also have locations in a number of other states but the one I am currently concerned with and posing this question about is in California. Our facility in Wisconsin is SQF Level 2 registered now for 3 years. The California location is AIB certified but we are being asked by a large customer of ours to have that warehouse SQF registered as well. My question is; Do I have that site stand alone under SQF or add them under the multiple site module to us in WI (we are the main site)? What would be the benefits or detriments? Also if we do register them as a multiple site can I act as their Practitioner or do they need one on site in CA? Your thoughts are welcome.

Thank You