I've seen lots of accessories for the Ruger Mini-14 and Mini-30, but none which in my own experience would be terribly effective as a "muzzle brake" (i.e. "ported"), though many likely would function as a "flash suppressor" (not the same thing as a brake). I'm assuming that the shroud is more "cosmetic" than functional, unless you're in a situation where you must carry the weapon by the barrel after firing.

As far as the recoil itself goes, the 7.62x39 isn't known as a shoulder-smasher, but the stock Ruger puts on these certainly contributes to amplifying what recoil there is. I'm very used to the.223, but never knew it "kicked" until I borrowed a Mini-14. Rather than (or in addition to) sticking something on the end of the barrel, you might check some of the aftermarket stocks (Hogue, etc.), especially those which would also accept an additionalrecoil pad.