Linux Ethernet Bridging - Feb 2009 - [Bridge] Two bridge and STP

Hello, my LAN today has this topology:

[router]
    |
[bridge]
   |
[switch]



[bridge] is a Linux box with 3 NIC, 2 of them are a bridge (br0) with IPtables 
for firewalling. The other nic is for management.

I want to have a standby 
backup for [bridge] in case of failure. I've read some documentation and I
came
in conclusion that the new topoligy will be:

      [router]
            |

      [switch]
      |           |
 [bridge]   [bridge2]
      |           |

      [switch]


with the two bridges STP enabled.

I think I had to:

- 
install bridge2 configured as bridge
- rsync firewall rules between the two 
bridges
- enable STP protocol on both bridges
- assign a lower STP priority to 
[bridge] to became master
-... enjoy?

Are my assumpions correct?