Are you shooting off a bench, bipod, or from positions like in a tactical comp?
You'll probably get answers saying that 10x is plenty for 1000 yards. I come from more of a benchrest background and like high-mag scopes. I'd forego the SS and find a used Weaver T36 or such if you're shooting off a bench. (you'll need an angled rail most likely) If you're set on one of those two, I'd choose the 16x.
My $0.02.