+1 on PMI mags. They are as good as Ruger factory mags.
Actually, I have 5 PMI 20s, 4 PMI 30s, and 4 Ruger 20s, plus a few no-names. I haven't used the Ruger 20s yet, but with the PMIs my rifle is as close to 100% reliable as a man-made machine can be. No malfs in ~400 - 500 rounds, largely Wolf.
According to the Mini-14 geeks on Perfectunion BBS, the new production ProMags are very good as well.