LinuxQuestions.org - web based firewall administration

I want to set a machine as a firewall so I will put two nics and have dhcp, etc... my first time doing this. I know there are distros such as smoothwall that are made specicicly for this, but I rather use a full blown linux distro like debian, and simply add on the firewall / web based administration part to enable me to add other services.

So my question is, is there something I can download and install that will act as the firewall part? I want some decent features like access logging, ability to block incoming and outgoing Ips/Ports, redirect port requests to another machine, and on a different port. (ex: have all port 80 requests go to a specific machine, but on port 5000), ability to limit simulatatious connections would be great too. That's kind of allot though, but if there's something, good, if not, I'll compromise.

Also, is there a way to make it so the machine can be powered off without properly shut down? This machine won't be on a UPS as my UPS downstairs already has two machines and I don't want to put more, or buy another UPS. This machine's main role will be firewall so I don't want to bother with having a UPS for it, just surge protection is fine, but I know ext3 corrupts very easly when a bad shut down, so is there a way to make it more solid?