Hi. I'm going to install Zimbra Network edition for about 1000 users.
I have some dudes regarding the hardware needed for that quantity of users.

First of all the idea is go to a virtualization scheme, and I'll thinking on RHEV or VMWare ESXi and for storage probably NexentaStor CE.

My doubt is regarding the hardware for this implementation. I'm thinking on 2 physical hypervisors, so I could have load balance and high availability.
For high availability this could be done by the virtualization plataform, but for load balance this should be done at the application layer, does Zimbra have any tools for that ?

Any suggestion is welcome.