SunOS vs Solaris 2 vs Intel/BSD for firewalls

[Steve Gaarder <gaarder @ actech . com>]

I'm planning to build a dual-homed gateway using TIS's toolkit.  I have
two choices for hardware platform: a Sparcstation 2 running SunOS 4 or
Solaris 2 or an Intel box running BSD.  BSD has the drawback that I'm
not familiar with it; SunOS 4 has the drawback that source routing is
impossible (or just hard?) to disable; Solaris 2 has relatively few
packages ported to it.  

Which do you think is best for this application?

thanks,

Steven Gaarder                              Network and Systems Administrator
gaarder @
 actech .
 com                          A C Technology, Ithaca, N.Y., USA