KitchenAid Grain Mills for sale | eBay
You can add barley, rice, and millet to the list. In fact, you can use this for low-oil, low-moisture grains. You can just attach it to any KitchenAid stand mixer, as this should be compatible with all models. It looks like a cup in which you pour your grain, and then at the bottom you get the freshly milled grain you'll use for your flour.