Linux Firewall / PPPoE xDSL Connection

I am new to the Linux world and had a few questions regarding configuring a Linux box to act as a firewall, as well as, connecting to my local xDSL service.

As mentioned I would like the Linux box to connect via PPPoE to my ISP (xDSL) and provide firewalling to the rest on my internal segment.

I would like to know what Linux distro would be the best for this application, as well, what NIC's are recommended since I will need two.

The hardware I have allocated for this project;

AMD K6-2 - 400
512 MB RAM
Adaptec 2940 SCSI Card
40 GB SCSI drive
Acer Motherboard

Any help would be greatly apperciated.