If you do something like this, I would highly recommend using a low cohumulone, high alpha American pellet hop like Horizon, Magnum, or better yet, Warrior for bittering. This way, you'll have smoother bitterness, you won't have to use a ton of it, or lose a lot of your wort via drenching the leaf hops.
I would recommend adding a warm whirlpool steep addition. So 60/0/DH - The warm aroma steep really provides added hop complexity since you're, 1) boiling the first installment for bitterness only 2) steeping the second installment in your warm 100-160 F wort during the chilling process for flavor/aroma 3) and then dryhopping the last installment in your 65 F wort for a week for added flavor/aroma.
What hops were you considering for the dryhop? And what is your goal, flavor/aroma wise?