
If you plan to build a lab for vSphere 6.0 you can use all the approches for vSphere 5.x (see also Building a vSphere 5 lab): usually using a nested environment (or three physical systems, if you have) as a common platform.
Of course, the other way to test new products it’s just use the VMware Hands on Labs that you can also “broke” or use in a different path compared to the one suggested by the guide. But having a local environment permit more flexibility and more time for testing or learning.
The big issue with vSphere 6 is that the minimim requirement are increased (at least for the ESXi) and now are become hard requirement! You cannot install the product without the right mount of resources. But after the installation you can try to tune your environment in order to free some MB of memory.