I think that a Creed movie would be excellent. How many bands have garnered more opinions - positive or negative - over the last 10 (or more) years than Creed?
Their story is pure Hollywood. They came from nothing to become one of the biggest selling bands of the last 20 years. They all, Scott especially, have interesting stories pre-Creed and then you have their acrimonious seperation.
Collin Farrell would be perfect as Stapp. As for Tremo, I will pitch a relatively unknown name. One of my favourite programs growing up was California Dreams. There was a character called Jake who played lead guitar (he also plays in real life). The actor was a guy called Jay Anthony-Franke. He's the first guy I could think of.
I found a few pictures of him from a website. The first one looks like an early Tremo.
http://www.jayanthonyfranke.com/images/FRANKE1.JPG
http://www.jayanthonyfranke.com/images/GUITAR.JPG