You could consider allowing a dynamic routing protocol to pass though the firewall devices, and use the transparent firewall option. However, I think you would need to consider the security implications of doing so very carefully, and secure the routing protocol itself as much as is possible (e.g. authentication, encryption, redistribution control, etc.).
Another option might be to consider using SAA probes and tracking, as per the recent article in packet magazine.
look at cisco.com/packet/162_4a2
and cisco.com/packet/162_4a3 for more info.