I know that tomcat can handle multiple SSL certificates by setting up multiple Connectors listening on different IP\'s, but is it possible to set it up on the same IP?
I am not sure, here if "SNI" is really relevant.
But in your case, the typical solution would be so called ssloffloading or ssl Termination: i.e. put your tomcat behinde an apache, which configured to use multiple vhosts / domain names on the same ip. You could configure for each vhost in apache to use its own SSL certificate.
There is a step by step guide for this topic here:
http://milestonenext.blogspot.de/2012/09/ssl-offloading-with-modjk-part-1.html