Choosing an AR pistol upper for a SBR build

[groundscrapers]

I've decided that I want to use a 7.5" 5.56 upper for my SBR build but I am running into a bit of a dilema. Do I want to run an A2 style upper, with a knurled hand guard. or do I want to run the A3 flat top with a set of troy battle sights. Thoughts?


The top is what that A3 would look like except I would probably use a sight base gas block.

Here is the A2 upper config

**ignore the fact that the first one is 9mm

 

[whatluck]

If I was gonna do an SBR, I would go with the A3, aimpoint, and a sling.

The only other thing would would need is some sunglasses, to help with the massive muzzle flash. I shot an 11" with cheap commie ammo and the thing made quite a flash.