i use a Dell Optiplex FX 160 (it was cheap to get on ebay) and a 2 GB SSD in it.
i start with the vmware image from here and copy it with DD to a 4 GB USB Stick.
Then boot a Partion Live Image and shrink the partions to fit into 2 GB.
After that copy with DD the USB Stick to the internal SSD Drive an voila it works :-)
now i hope Update 4.2 next month will work anymore so i can use nativ Push in Gira App without my workaround.
And a friend of mine told me there is a chance to get the HomeServer as a Software only Product in future (to Run on NAS Devices etc.)