So I am new to home brewing and my girlfriend is GF and is wanting me to make her a GF chocolate stout. I am going to use the Double Chocolate Stout that I found on http://www.glutenfreehomebrewing.org/showrecipe.php?recipeid=63 but I am wanting to only do a 1 gallon batch so that I can fine tune it and when its perfect I will make a 5 gallon batch. But to do the one gallon should I just divide all the ingredient numbers by 5? Also I'm wanting to add coffee to it, what would be the ideal type of coffee, dark roast, light roast and should i use whole bean or grounds when I steep? All advice would be very much appreciated.