Virtualization Concept throw Network

[Xahid]

I am thinking to build the conceptual design of Virtualization with four of my experimental Servers, but would like to know what tools do I required, after little research, I got VMware vSphere Hypervisor which can configure the Virtual environment for one server, but that is not what i want, maybe Linux KVM ?
here is a concept,

Physical Servers are all connected throw out gigabit LAN.


I want all of them to be configured as One Virtual Server or at least they can share the resources (with of course limitations of physics)
as shown below,


So that, I can create as many Virtual Servers as many i want and distribute the resources among them.