Linux router distro with support for ADSL2+ and WAN load Balancing.

I am looking for a stable Linux Router Distribution with support for ADSL2+ and Wan Load balancing capable.

I am planning to build two PC-router with intel Atom Dual core, DDR3 1 GB of RAM.

I need a Stable and powerfull Linux distro to power up this two machines and be able to load balancing or fault tolerance between this two machines.

I found on wikipedia a list of Linux Router Distros which is very interesting.

The ones that i like more are:

Vyata-commercial License (most closes competition to Cisco)
untangle-Free/Commercial addons (It looks promising)
M0n0wall-Free (for Small embedded systems)
Zeroshell-Free (Small business server)
clearOS-Free (based on freeBSD)
RouterOS-Commercial (for use with routerBoard)

Does any one have experience with any of those Distros. Also wich one of those distros will address my needs of adsl2+ and Wan load balancing/ Wan fault tolerance. Since I plan to add an ADSL2+ PCI card to each one of my routers PCs.

Resume of what i need:
stable router OS
Support for x86 architecture
Support for PCI ADSL2+ modem
Support for Load Balancing and/or Fault tolerance.

Others:
Web interface will be a plus but not needed.
CLI interface with remote SSH will be perfect.

Ok. If I understand your post correctly, you are creating a PC router using an Atom dual-core CPU w/ 1GB of RAM. Most any current distribution can be configured as a router quite easily. You might look into Debian as it is a very modern distribution used in a lot of similar situations. It is the core of Ubuntu, Mint, and a number of major Linux systems. It is very configurable, and supports most all modern hardware.

Thank for your reply.

Does any one knows a good application to do routing under debian?

I will have some activity next week on this project and I will give debian a try.

There are also a number of good online FAQ's and How-To's about how to set up a Linux system as a router. The Google search terms "Linux router configuration" returns a number of them, including this one at the top: Linux gateway/router - (another) HOWTO