Redwolf...Deepfire makes a 68 round mag for $7.35, I have some of those too, and they aren't bad either. I honestly can't tell the different between Deepfire @ $7, King Arms @ $12 and Tokyo Marui @ $22 except for the TMs have the nicest, strongest springs and are effected by detritus the least.
G&P makes a midcap. I have one, if you wanna buy one, like, $10? Never been used. Has an X in sharpie on the bottom, but you can't tell unless you're looking.