ADSL routing with 8 IPs using a SpeedTouch USB + FreeBSD - Possible?

[Edmund Craske]

I've just found an ISP that offers wires-only 8 IP ADSL, and I already
have BTOpenworld Home 500 plus a SpeedTouch USB and a FreeBSD NAT
gateway. When my contract with BTO runs out, I'm told I can keep the
filter box and SpeedTouch USB, and freely skip over to a better ISP. My
plan is to alter the current setup so that I have a DMZ with some
FreeBSD servers in it, each having a static IP, as well as good old NAT
serving up the net to my home PCs. Firstly, does anyone know if the
SpeedTouch software minds handling lots of IP's, or, as my intuition
tells me, are the drivers between level 1 and 2 of the OSI model anyway,
leaving FreeBSD's TCP/IP stack to do whatever it pleases? If it is
theoretically possible, how would I go about instructing FreeBSD to
route packets bound for the different IP's to my DMZ network?

</rant><breath>

Thanks,
Edmund Craske
Bitesize FreeBSD geek