These guys have AICS chassis mags in stock. I haven't purchased anything from these guys before so I can't vouch, will update when I receive my order. Prices are high, but considering these are sold out everywhere I pulled the trigger.
http://www.mackspw.com/Item--i-MHSAI3902
Tom
http://www.mackspw.com/Item--i-MHSAI3902
Tom