2U chassis (was Linux Router Kit)

We are trying to roll our own server/router/accounting box and have everything speced out but the chassis, we need to find a PC rack mount chassis that is no higher than 2U ( 3.5"). The co-los we use charge us not only by bandwidth but by real estate, we need to cram as many boxes as we can in the space. In fact if you know of a 1U (like the cobalt boxes) that would be even better. Any clues would be greatly appreciated. Geoff White GW Communications Inc.