Oh, and for the STANAG I figured I should just ask them. Got the answer within 24h:
Thanks for the email. The magazines will be housed in real magazine shells and therefore will be as realistic as possible. Our time line for production and release is, at the moment, quite uncertain. We have made several design revisions lately that have forced us to take a few steps back. We hope that by doing so the magazines will be accepted by the airsoft community as the highest quality and most reliable magazines produced for GBB rifles to date. MSRP is also hard to gauge as until we receive manufacturing quotes which is at best several months away. I wouldn't expect the price to be below $60 MSRP.
Having said that, if you are determined to get a GBB rifle, the KJW is the absolute best there is. I wouldn't let the C8 magazines keep you from buying it. I would certainly expect that stanag magazines are on the way from a variety of manufacturers over the next year, ourselves included.
If you have further questions please don't hesitate to email us.