It mentions somewhere in security that automated turrets are just drones mounted into the wall (or on a track) with a wide angle traverse to their weapons.
As such, I'd decide how big a turret you want, pick a ground drone of appropriate size, use the stats for that but halve the price and strip out the movement systems to represent a turret-drone.
Not sure about the smart platform. Compare its cost to some drones - if it's really cheap, have it be a one-hit wonder. If not, just slap some mini or small drone stats on there?