From what I have read it would appear that JMS Multisite will work for me. However, I would be grateful if someone would confirm my understanding. Apologies if this information has already been discussed.

1. Slave sites can display selected content articles from the master site.
2. SOBI2 can be installed on the master site and all slaves can display/search SOBI2 contents
3. Articles can be added to each slave site and not be viewed on other slave sites or master site
4. Each site can be installed with it's own database and Joomla files independent from master site
5. Each slave can have it's own template
6. Certain components can be shared from master to slave

Many thanks

1) YES with the "Article Sharing for JMS" that is an additional extension to add at JMS Multisites.
2) YES it is possible to share SOBI2.
It is in the list of extension that can be shared.
www.jms2win.com/component/content/article/135
3) YES but if you install the "Article Sharing for JMS" it is possible to read and display any articles coming from any website defined in JMS Multisites.
4) YES but becarefull if you want to share extension like SOBI2 you will need to have MySQL user privileges to share the MySQL tables between different DB
5) YES. See tutorial video CP-05
www.jms2win.com/tutorial#jms12x-CP-05
6) YES see the limited list of extension that can be shared
www.jms2win.com/component/content/article/135