This machine I built for my mob arena. It uses T flip flops and an item sorter to take the item of your choice and dispense an item based on the button that is pressed. It will shoot out any items that aren't acceptable. More buttons/options can be added to or taken away from the machine by repeating the design. I have set it up to accept coal and to dispense mob eggs. It will give an exact amount based on the stack added if added all at once. So in other words, if you want five of two seperate items, push desired button, add five, wait and push next button, add five. Don't push buttons after putting a full stack in or throw your items too slowly with q as you might not get Exactly what you paid for.