What to buy to use vSphere with PowerCLI

Hi,

I am somewhat new to ESX but have used PowerCLI extensively over the last six months.

However, I find it difficult to figure out what I need to set up a vSphere infrastructure, however small, at home; specifically if I want to use PowerCLI.

What do I need to buy to be able to run ESX on one or two hosts and use vCenter and PowerCLI to administer the hosts? Does the "Essentials" kit do it? What licence do I need? I see that I can download PowerCLI, but will it work with just any ESX or vSphere installation?

Please advise.

Thanks.