RIS hop help

[johnmac22]

I am looking to brew my first RIS and let it sit until this time next year (hopefully) but I am not sure how to approach the hops for a RIS. Here is the grain bill hat I have so far. Feel free to critique the grain bill and add your thoughts about hopping.

5 gallons
OG: 1.095
90 min boil

~75% Base
~16.8% Chocolate/Roasted...Split about 60/40 between chocolate and roasted
~6% c120
~3% flaked oats

I have a ton of Magnum that I was thinking of using to bitter but am unsure what else to use and when. I am looking for the hops to bitter the beer accordingly, but not be too noticeable. Thoughts?

 

[pumahunter]

here's a decent tool I've used a few times trying to find the right hops...

http://hopunion.com/aroma-wheel/

I'm doing an RIS soon gonna use magnum, columbus, chinook and challenger