Firewall or bridge?

["David Gaudine" <david@annette.concordia.ca>]

I've been reading about firewalls, and can't figure out what to put in
"interfaces" for my situation.  I now think that the problem is I need a
bridge rather than the kind of firewall I was reading about.  My
situation is:

- Static IP with public addresses
- Gateway 132.205.50.1 is on the "internet" side, all other 132.205.50.x
on the "inside".  This is why I can't figure out what to put in
"interfaces", since the net mask would put the gateway on the wrong
side.
- router is far away, and expects to be connected to a switch.  My
understanding is that to use a firewall I'd have to get the gateway
configured to address everything to my firewall, and I don't want to
mess with the router.

My questions are
1) Am I right about needing a bridge?
2) Normally a bridge has no IP address and can't be used to provide
other services.  It can't even be accessed remotely.  Is there a way
around that?

David