Some people mount the SmoothStepper in the computer, some in the cabinet, your using a laptop so would need to put it in the cabinet or make another box. Ethernet one will require a 5v supply which you can grab from the computers USB if you wish (chop up a USB cable), USB one can use the power from the USB direct or an external 5v.
The one you linked to will still have to be mounted somewhere so not much difference, it will be a bit smaller I suppose but likely not much, the SS is only 70 x 90mm
Now not saying you should go for the SS, just saying they all have their place depending on requirements, as mentioned before the CSMIO would be the one I choose but my requirements are not the same as others.
Hood