Looks like a great recipe. Be sure to adjust your efficiency, you'll most likely be sparging less than usual in order to keep it down to 3 gallons. You're getting a lot of color from that brown sugar, I expect. I also agree the oak is probably not going to do much in the primary, although you may get some very soft flavors akin to oak barrel fermenting, might be worth a shot. You could also add a little oak in secondary too if you wanted a bit more oak character. I would suggest balancing your water to favor chlorides if you can, that will accentuate the maltiness and keep the bitterness from tasting too harsh. And as for aging, it will keep getting better and better the longer you let it go. But there's no problem in tasting some early, it gives you a good idea of how a beer changes as it ages. But definitely put several away for a couple years!