US model will be US only and manufactured by HK USA due to their funny gun laws, the SL8 was different in the USA as well.i didnt see anyone post this information yet (correct me if I am wrong on that front)
but it will be designated the HK293 in US (an probably Canada) and HK243 in other markets.
Bolt and barrel have been changed and is not easily interchangeable with the G36 (hence it should not be considered a weapon of war by the German gov't)
And lastly, yes it should take AR magazines
We will get the HK243 from germany in canada just like our SL8's all came from germany