Managing large numbers (100+) of Debian-based machines

[Laurence Hurst <L.A.Hurst@lboro.ac.uk>]

Hi folks,
I am looking at possibly deploying Debian (or a derivative thereof) on a large number of machines (initially 80 but I fully expect the final number to end up being in excess of 100) which are intermittently connected to the network (due to multi-boot setup). I was wondering if anyone else has a large(ish) installation base and what tools they were using to manage the machines (especially when it comes to patching)? On this scale manual ssh methods become unmanageable, even using the likes of pdsh and before I even consider the fact the machines will not all be in Linux at any given time. Unfortunately I have no budget for this project so an Ubuntu/Landscape solution is not workable. Ideally something usable by non-Linux (but technically competent Windows) administrators would be nice (e.g. a "point and shoot" web-interface to mass deploy updates). Does anyone have any suggestions of existing projects which fit this bill or am I going to have to roll my own solution?
Thanks in advance
Laurence