brickhouse vs an actual router

Not really sure what you mean by brickhouse. If you're talking a hardware router (like a linksys) vs software routing (like using linux) I'd say both have their plusses and minuses. I use a linksys myself because it's easy to configure, and it uses very little space and power. If you decide to build a box for this purpose, you need to find somewhere to put it, as well as a way to configure it (maybe an extra monitor), and you're going to use more power running it all the time. If you need the best security and config options, a separate machine would probably be better. If you want something simple and easy that offers NAT firewall capability, then go with a hardware router. The performance differences between the two options shouldn't be extremely noticeable in your case.

what's your brickhouse setup? one or two ethernet ports on the router computer?

Brickhouse allows software routing...

Which is better...unless you have a dedicated router computer with a nice firewall, then software is better, or if you are only willing to pay the shareware fee.

For the most part, hardware router is better, since it doesn't have to be turned off (definite + with the energy bill so high in Cali), doesn't tax the first machine's CPU/connection, and easier to setup, IMHO...(I remember the horrfic experience with some of the other software solutions)