Hey jlutterloh,
You can get the user object using the rest API. The user object contains the sso_id. The code below will create a component that outputs the SSO ID for current user if the current user has an sso id. The check in the if checks if the user has an sso_id.
<#assign user_obj = rest("/users/id/" + user.id)>
<#if user_obj.user.sso_id[0]??>
${user_obj.user.sso_id}
</#if>
You can see the type of information you can get from the user object by just calling the restapi url:
{communityurl}/restapi/vc/users/id/{user.id}
Hope this helps,
Yuri