FOSS Software Deployment/System Management?

Farmer Pete writes: I've recently been put in charge of researching, testing, and ultimately deploying a software distribution system (i.e. SMS, Landesk, XBox, etc) for a medium sized company (+2000 computers). In the past, we've handled software installs either manually, or using a PSEXEC type push tool. Neither of these systems are very useful when dealing with so many computers, many of which aren't turned on, aren't reliably connected to the network, or are in remote locations with a 256kbps link. We need a system that handles software deployment using a good chunk of criteria for it's deployment. We need good logic as well as remediation steps if the deployment fails, and most importantly verification that the software was in fact installed! Making policies permanent would also be good, such that if any computer ever gets scanned with Adobe 7, it will upgrade it to version 9, not just the computers you selected who had version 7 last week. Also, having the ability to do extra system management such as configuration checks and inventory.

I've been looking around, and I've been very shocked to see the lacking in the FOSS community for solutions like this. It appears that OCS Next Generation has the most refined solution, but it's far inferior to any commercial product, and it lacks many of the features that we require. For instance, it doesn't have a force check-in option, so deploying software to a single computer after it was requested becomes impractical. It also doesn't have much in the way of logic for installing software. Does anyone know of a good FOSS solution? I really don't want to pay $50k to 250k for a commercial product (not to mention the perpetual license fees).