Hi,
I don't have any direct experience on QueueMetrics running on Windows 2003 server but, being QueueMetrics a java based system, I don't think that it will have problems with Tomcat on Windows machines. There is not, moreover, an installation package for this OS and it should be installed manually as webapp application.
QueueMetrics will be supported even if installed on Window machine. The support will be, as actually is for Linux machines, related only to QueueMetrics issues and not to the system integration.
The requested hardware is related to how many concurrent agents you have to manage; i.e. how many concurrent live agents page and realtime you need to serve.
Actually, a mid range desktop is sufficient for small/medium sized call centers. Being a Java application, I suggest to have a lot of memory available for it.
Regards,
Marco Signorini.