Barrel change for Ruger Mini 30

[kef]

I own a Ruger Mini 30 in stainless steel. I have it in a SCAR stock. I would like to change the barrel out to something heavier and in an 18.5 inch stainless with some sort of porting, cage or brake on the muzzle. Can anyone point me to someone other than Accuracy Systems in the U.S. that I can't use as it is cross border and the pretty much impossible.