The best build I found that worked the most efficiently for me as a mid level sneaker like that was the .223 eyeshot sneaker build, I can't remember specifics, but it is a basic sniper kind of build, trading out certain aspects to suit sneaking with a 223 pistol.
I run a solar scorcher eyeshot sneaker build now, but solar scorchers in general are not easy loot to acquire in large doses, and when combined with a motion sensor, make one of the most expensive and squishiest build combinations of all time.
The biggest difference and the reason I find it so hard to go back to a .223 build, is the minimum damage, in some cases you fail to crit and end up dealing like 10 damage with a .223, where for a scorcher that will never go below 50 or somesuch.