Hi,
i would set up a network which spearte zhe different sites. The core switches should hold all information about the vlans. Configure vtp server on both cores.
When it's possible seperate the departments through vlans. Between the core switches you should configure a channel. The catalyst 2955 should connect to the every core switch through a trunk or to one core switch with a channel. On Access-port enable portfast and so on.
When you will read the configuration guides you can see whats possible.
Regards
Peter