Hello and welcome to the communities.
Check the HCL for all of the available supported options. The Iomega options are a cheap approach. If you want unsupported but stable, I tend to just use CentOS and make my own.
There are any number of applications such as Openfiler that can be used in low budget of lab scenarios that would be perfect for most of your requirements. However.
I VMware certified, reliable,
Those requirements suggest a production environment, and based on this, I would recommend not looking at any "software" solution at all, but a hardware one.
You may want to look at StorMagic SvSAN, Vmware 4.5 & 5.0 certified and is fully integrated into VMware's vCenter.
SvSAN is feature rich and offers great flexibility and scalability for a very resonable price.
Checkout our website www.stormagic.com, I have also attached the SvSAN product brief.