The new SAR-3 rifles take converted AK-74 magazines.
Users have reported 100% reliability with 28 rounds loaded.
There are also steel magazines made specifically for the .223 AK's. These are called "Weiger" mags, and are available from Inter Ordnance. I do not know if these metal mags will work with older norinco and polytech AKs.
I believe that progressive Arms or K-var have .223 waffle mags available, but have not checked on this.
And once all this is said and done, yes, 7.62x39 AK mags are easy to find.
BUT, the 5.45x39 mags are as readily available, and cheaper!