Pro Sites and SSL Certificates on Multisite Install

Hi. I've searched the forum and haven't found a solid answer (or at least a recent "state of the market" response) so I'll toss this out for your feedback...

I'm putting together a Pro Sites project and one of the features I'd like to offer to premium members is a child theme I created to build Wordpress sites that can be run on Facebook page tabs.

In a stand alone environment, I have set up an SSL on a single domain and then created multiple subdirectories with unique WP installations that use this child theme so that all of them can be covered by the top level SSL and be compliant with Facebook's new requirements.

Is there any way to accomplish the same basic thing in a Multisite environment with Pro Sites (and most likely domain mapping)? Or would I have to think about requiring these clients to also get their own SSL - and if so would domain mapping work with the SSL (ie could they just get an SSL for the domain they want mapped to their subdomain on my Pro Sites installation?

Thanks for the assistance. Chip