What do you see the final product looking like? Do you want to offset the caramel from the amber with a citrusy hoppiness from the amarillo and cascade? Or a more subtle, woody and floral presence from the NB and willamette?
I would either group it one of three ways:
Amarillo/Cascade - Citrusy deliciousness
Northern Brewer/Cascade - California Commonish combo
NB / Willamette - more floral notes, smoother, delicate
my 2c. Good luck! What's the grist look like?
Primary: Black Storm Ryesing (CPA),
Bottled: Tri-fecta Tripel (8/2010), Aficiando Smoked Bourbon Brown, MurphRYE's Pale Ale
Kegged: Oatmeal Stout, Winter Wheat
R.I.P: Dr. Suess's "Green Hops and Rye" Pale Ale Murphy's Law IPA, Honey-do Hefe 2.0, Power of Pine-Sol, Rob's Brown Ale, Wolfpacker's Wheaties II
Project(s) Completed: Cooler Mash Tun (dual-braid), Kegerator, Keggle Conversion, 50' Immersion Chiller.