Have u try a Linux Router? I did…, there is much and some of it i have try.
Here the list:
– Freesco (this is my first Linux Router with only 1 disk, without Harddisk)
– Endian (use only 1 day)
– SmoothWall (Just try installation)
– IPCop (use until now)

Freesco, is the first linux router that i used. It’s very flexible for me. It can became a proxy server, print server, web server, a router, as music player, and etc.

Now i user IPCop, it’s simple and not too complicated.
With IPCop 1.4.21 I can user AdvProxy as addin. It’s use squid 2.6.STABLE21.
Until now there is no problem with my IPCop…
With IPCop I Can:
– Control who can browsing to Internet
– Control who has bandwith more big or less
– Band any website, like porno n etc.
– See instanlly what site from user browsing.

For now I recommend IPCop for You. But of course it’s not the best one. It’s depend on your bussiness.