Syncing Multisite domains with primary site

My requirements are as follows:
One primary site (root WP MS install) – with a particular layout and content
Any number of derivative sites – each an exact clone of this one, with only the logo being changed.

For this purpose, I’ve installed WPMS, but am unable to find a tool or a feature that will help me keep these sites in sync. Please advise on what options I may have.

Thanks in advance.