You can try and find some USA "frankenmags" (look like AK mags) on the EE - they are the only currently made 7.62x39 mags that work reliably. Never had an issue with them in my Colt 7.62 upper. Although, those of us with 7.62 uppers are eagerly awaiting the release of the C-Products mags.
Your best bet would be to hold out until the end of the month (tentative date of Apr. 24th, I believe) when C-Products release their 7.62x39 mags. C-Products have shown themselves to be a standup company that makes excellent magazines. If their past perfromance is indicative of what's to come, you will be best served by holding out for their mags. I know all of my USA frankenmags will be going on the EE when those are released.
Until then, It's USA frankenmags or a big headache with other brands.
ETA: There is a thread going on in the magazine section (probably a better place for this post, or info on mags in general) about C-Products 7.62 mags. I'm sure Larry (C-Products) will post the actual release date for the mags somewhere in there (hopefully sometime soon).