Laptop as a Firewall Gateway Questions

My laptop has two network cards with two plugs and I was thinking of using it as a IDS / Firewall.
I know that there is a software firewall OS that I can load on the laptop that will include virus scanning / firewall etc functionality. I know it runs on Linux and is a dedicated IDS/Firewall OS.
However I forgot what it's called. Can someone help me out with a reputable one?

Also can someone advise me on this network architecture configuration?
I was planning on running this:
Comcast Cable Modem to Lappy (acting as a firewall) then lappy to Linksys 54G DD-WRT acting as a WiFi bridge then two additional Linksys 54G's with DD-WRT or Tomato Firmware acting as repeaters so I can have strong signal per each floor of my house.

Currently I have the Linksys's configured and had them running fine for months however now my configuration is Comcast Cable Modem to the first Linksys and then the others as repeaters, I don't know how much issues would be throwing the laptop as the network filter. Would I experience routing issues? Mainly I want a good IDS / gateway with automatic viral filters that could act as the first line of anti-malware defense and using different AV engine before the malware hits the home desktops.

Thanks!

 

I am sure that FreeBSD can be trusted, here's how; http://www.instructables.com/id/Build-your-own-gateway-firewall/


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I recall there used to be a FREE for Home Use BSD or Linux based Firewall / Ad blocker and Anti-malware scanning gateway software that could be loaded as a single purpose OS on old PC.

However the company also sold lic for corporate users so it was well mantained. It's name escapes me and that's what I am trying to find.

 

Is there a software package that I can run in Windows that will turn my old lappy into a Anti-Malware and firewall gateway?

 

Here's a few Linux/BSD options:

http://en.wikipedia.org/wiki/List_of_router_or_firewall_distributions

Should be able to find what you need there.

Also:

http://www.distrowatch.com

HTH

 

Something like this too?
http://www.astaro.com/landingpages/en-worldwide-homeuse