Send me an e-mail at firstname.lastname@example.org
and I will get you all the specific pricing information you are looking for.
I get around 3050 fps in a 34" Lilja barrel but I do not push the round really hard. This is with a 300 gr ULD RBBT Wildcat Bullet.
I do not have any hands on experience with the Rock Creek barrels as I generally use Liljas for all my rifles unless my customers want some other brand. Again, you are the boss, I do what I am told.
The McMillan is a good action for this round. Drop me an e-mail and lets talk this over a bit more.
As far as a brake goes, I would recommend a Holland. I will get you more information back in the e-mail.