Dry hopping

I am getting ready to brew a 5 gal New World Porter. My hop shedule:
.74 oz Columbus @ 60 min
.74 oz Columbus @ 30 min
1.90 oz centennial @ 0 min
1.90 oz Columbus @ 0 min

I want to dry hop in the secondary with either the columbus or centennial; the other will go into the boil at 0 min
any thoughts?

Thank you
Buckwheat2

 

If it helps here is my grain bill for the New World Porter
8lbs 1.9 oz 2 row
1lb 15 oz Munick Malt
14 oz Caramel 120L
7.8 oz Cara pils
7.5 oz Chocolate Malt
6 oz Black Malt

I am always open to suggestions

Thank You