I believe those responsible for the Arma 2 version of the Strykers were: ExplosiveAids, Stiltman & RicoADF. If anyone can give them a shout or otherwise knows how to contact them maybe we can get this ball rolling.
Here is a link to their old mod. Mayhaps someone can shed some light on the situation?
http://www.armaholic.com/page.php?id=12380
I went ahead and added this to my Arma 3 and the Stryker showed up but the weapon systems weren't there and aside from getting into the passenger seat and checking the inventory, these vics were pointless. Perhaps I am doing something wrong? I certainly would appreciate some help if some can be spared.