I personally would not recommend using an Objective-Adapter - as already pointed out, some auto focus lenses won't work (which is what happen to me). If possible, only purchase lenses that are specifically made for your particular camera mount.
It will definitely let you put an A-Mount lens on the camera but autofocus will not work if the lens requires an external motor. For that you need LA-EA4. I don't know if the lens you're talking about requires an external motor.