That looks very similar to my Death by Chocolate Stout recipe, only I didn't use oats and added some roasted barley. I also used Fuggles for the bittering. Ok, so it's an entirely different recipe, but here's what I think. The only thing I would do different is cut back on the chocolate and black patent malts a bit. Not much, but be aware that it doesn't take much of either of those to have a distinct effect. I only used half a pound of chocolate and a quarter pound of black patent in Death by Chocolate Stout and the chocolate flavor is definitely there. Best of luck to you and I think your recipe will turn out great.