I use a loud dodge build paired with suppressor skills. The 3 less concealment points are canceled out by my dodge skills. Thanks for the tip.For stealth? P90, its cheap and does the job
For loud? Remington with suppressor and specialized killing (you get 206 damage per pellet
If you can spend some money use the KSG or use a sniper.
But i guess the L85A2 is better