Personally, I would not put a fixed 20X on a gun, because:
1. I shoot in some hot environments, and mirage can be awful on a fixed 20X.
2. In low light, they simply are not useable.
3. FOV, though good for a 20X optic, is very, very restrictive.
I should specify that if the gun in question will be used exclusively in good weather, on a known distance range, and always in full sun, it might be OK; if not, I'd look elsewhere.
I've sent rounds down range at 1,000+ yards with a 10X scope and been happy with the results. If your purpose is small groups at 1,000 yards, a 20X is a good tool; for anything less, I'd consider other options, like the 10X SS.
OS, I don't know of any government contracts with SS, but I do know they are in use in military and LE rolls.