I would personally use Columbus to bitter, and use Simcoe later in the boil. Reason being, I feel that the unique flavor and aroma of Simcoe would be wasted if it was used for Bittering.
Kegged:DIPA,Pumpkin Stout,,Munich Helles, Chinook/Simcoe/Citra/Amarillo IPA
Bottled: Blackberry Mead
Primary #1:Mosaic IPA
On Deck:APA,RIS,AB Clone