IIRC, you can use VMS (or VMS Basic) to do exactly this. If you want to have all your sensors use the same set of signature settings, you should be able to configure a single template and then push it out to all the devices your are managing from that VMS.
The key is to assign all of the sensors to the same management group in VMS.
The following link might provide more info, as my hands-on time with VMS is very limited:
http://www.cisco.com/en/US/products/sw/cscowork/ps3990/products_user_guide_chapter09186a008018d985.html
I hope this helps,
Alex Arndt