I want to place a security box outside of my router to the outside(internet)......On this box, I should have an IDS/Firewall/TrafficGrapher/TarPit....Of course it will be running linux...........But my problem is selecting software to use for this purpose. It will be under moderate loads(30-50k) @ all times........Any ideas for what to use and/or what I should put on the box?

Specs:
2x300p2(dual proc)
256 mb ram
9 raid 5 scsi