I would add the water/honey mixture to the primary, let it ferment for a couple weeks first. Then take 4 oz of your favorite coffee beans, roughly crack them, add to a 5 gallon paint strainer bag and add to the fermenter. Wait a couple days then sample, and sample every day after until the coffee flavor is at the level you want, then pull the bag. Adding the coffee beans this way is the best way IMO to get that fresh coffee aroma into your beer. Good luck !
Edit - I also would not use a lot of honey - it'll take longer to ferment, make it drier, and might change the balance of the beer more than you planned. I personally wouldn't use more than 8 oz. Just me.