I'm helping a friend (who's left handed) put together an AR.
When I've taught at work, the lefties have to adapt to department owned (stock) rifles, and it seems like most of them get pretty good without any ambi controls.
Budget is also a concern. As I've shopped around for ambi parts, it does add a bit of cost to a build. Some things like the selector I actually had lying around, but a full ambi lower is $$$!
So I'm wondering for those of you that are left handed, what if any ambi controls are helpful and/or necessary?