Designing a Security Lab?

RanmaPlex asks: "I've been asked by a university professor to design a network security lab for use by about 15 students. Designing a course was asked earlier, but little info was discussed on equipment. It needs to be vendor independent if possible. I've got ideas on using virtual machines, patches, IDS, firewalls/vpn and sniffers but would like to know what the Slashdot community can come up with."