Chocolate Milk Stout recipe question...

So I want to brew a Chocolate Milk Stout and picked up the following for it...

6 pounds Breiss Dark LME
12oz. ground Chocolate Malt
12oz. ground Blackprinz Malt

4oz. Chocolate extract.

I also grabbed Wyeast 1187, Ringwood to go with it...

I plan to steep the malts for the standard 20 mins and then add the LME towards the end of the boil.

My question is, should I go with nibs instead of extract? And which hops would be best?

Also, Am I putting too much Blackprinz in it? I ground the two together and originally only meant to do 4oz, but grabbed the wrong bag.

Thanks and sorry for the questions, this will be my first non-kit brew.

Your receipt is pretty close to the one brewed. I opted for the cocao nibs in the secondary for 14 days. My hops were 1oz cluster @ 60 mins and .5 oz of cluster @ 30 mins . Still one of my favorite brews to date. Are you going to use lactose in this brew?

Yeah, forgot to add I have a pound of lactose. One recipe said toss it in for the full 60 minute boil while another said just for the last 10. What would the main difference be?

If i can recall i added mine just after everything settled down from the 60 min additions. about the 50- 45 min mark. I don't know what the differences would be 60 vs 10. Sounds like i need to do a re brew