Galil mags worked well in mine, cheap fron the US. I beleive it worked fine with the stock mag release but I don't remember exactly if I did the Galil conversion before or after getting the mags.
The importer that rymes with Mashtech Marmory had the newly made promags in stock but I never had luck with promag magazines so I couldn't recommend them, get the surplus steel waffle ones. Mashtech will add things to their store ans import them for you though.