Good old Marui mag very reliable
http://www.evike.com/Merchant2/merchant ... de=MAG_AEG
The 30 rounders, cheap but i have heard they work well if they are oiled up. And sometimes they dont sit well in the magwell so you may need a little strip of ductape inside your magwell if they are to loose.
http://www.evike.com/Merchant2/merchant ... de=MAG_AEG
130 round G&P here
http://www.evike.com/Merchant2/merchant ... de=MAG_AEG