At first I was thinking that you're looking for too much in a home router -- (BTW You can get home routers + firewalls for $10.00 and shipping now after rebate from Tiger. (I think I read about that at openacs.))
You want, a lot.
But check out /. today, someone's got a linux distro for a linksys wireless broadband router. 80211g and only one broadband connection.
Wow, that's just about what you want! Inexpensive but brand name hardware and r0ll your 0wn linux goodn3ss!