Licenses: 1 QlikView Server Enterprise Edition + 1 Additional QlikView Server Enterprise Edition (Cluster license) + 1 Publisher license. Install each one of them on a separate machine. Especially useful for the cluster set-up is chapter 17 Clustering QlikView Servers in the Server Reference Manual.
Publisher: configure your publisher machine to reload all documents and publish them to a shared document folder (on your network). In the reload task (System->Performance tab), you can specify for each document on which node it will be available. The default is "On all nodes".
This is only free advice. If you are serious about obtaining an enterprise QlikView set-up, contact your Qlik partner. They can provide you with specific information that applies to your situation, and the best possible set of products & licenses.