There is currently no way to duplicate multiple models with a single click. You can duplicate them individually and manually position them with offsets. I just did one to see how involved it was and it wasn't very difficult at all.
That is also what i found but if you hit center and arrange they all stack in the center. It would be nice to have a separate arrange feature without center or be able to select more then one model to move. I ended-up redrawing the model with the duplicates.