[Soekris] OpenBSD pf transparent bridge - hardware tricks

[Art Arica3D]

Hi,

I have done all my firewalls to date with a dedicated admin port (3
legged) and I'm limited by this particular project to only 1 incoming
network drop and I'm debating my options.

Normally I have a single network drop from ISP, I put in a small
switch, then feed two incoming ports on the firewall.  However, in
this case I can't come up with the extra power drop or space for a
switch... I'm limited to just put in a 12 inch x 12 inch footprint
with only 1 power drop.

Hardware question:
I know of some PCI powered switches, has there been one found to be compatible?
Any way to make the lan1641 act as a 4 port switch that acts
independent of the OS?

I know these are long shots, but figured someone might have tried to
solve the same problem here.

Thank you.