I'm getting ready to order a new BTO RiMac (waiting to see if a 27" refresh is coming soon.) This will be my first Mac computer, so I need guidance on storage. I plan to go fully SSD, either 256 or 512 GB. I will need enough storage to run 2 - 4 virtual machines, each with about 30 GB of space. Most of my data-at-rest (pictures, music, etc,) are already stored on an external drive. Since I'm unfamiliar with OS X, does anyone know if I could get by with the 256 SSD, store the VM virtual drives on an external drive (maybe a TB drive) and be able to access the VM's through VMWare on the external drive? I know in a Windows world this will work, but I'm not familiar with OS X. I'd prefer to stay fully SSD instead of the Fusion Drive. Thoughts?