+1 for moving away from RM. Vanilla networks nowadays can do most of things that you'll want to accomplish on your network. Depending on whether you use all of the functionality CC offers will depend on how easy it will be. One example is WDS, once setup correctly you can build machine in <1hr compared to the RM way of all day. We've moved (nearly) all our networks away from RM and the school's say it's now much better.
On the server side, we use a Dell T630, single Xeon, 32GB ram, 4 x 1TB HDD for £1991