No brainer is right. Keep the mini, pass on the Bubba'd M1. BTW, Ruger is selling factory Mini 14 20 round Mags on their web sight for $29.00 ea. A buddy of mine just received 4 of them. Back ordered but the wait is only about 3-4 weeks.
Edit,
Easy way to tell if an M1 receiver may be an M1C; The M1C has five holes drilled in the side of the receiver, 3 are tapped, two are not.