I use a vmware workstation (my version is 9) to practice vCenter with cluster, 2 ESXi host, vCOPS, vDP etc. To add a share storage, I use a Linux box (separate system) with NFS share so that i can use it as a share datastorage for esxi hosts. This NFS share also configured and shared for two esxi hosts by IP address. Sometime I use Microsoft iSCSI Software Target 3.3 (software-based and hardware-independent iSCSI disk subsystems in SANs) installed in windows 2008r2 for iSCSI Disk for my ESXi Datastore. This iSCSI Drive can also be a map as pRDM to a VM.
My laptop is 12GB RAM, Core i7, Win7x64.
Note: My Intel i7 support VT. so i can also run 64bit VM OS.