
My Self |
Assuming you don't already have a social trait or a race trait, you could take the Fiendish Sniper tiefling race trait (from Dirty Tactics Toolbox).
+5 on Stealth checks made following a sniping attack. It's even a bonus, not a reduced penalty! ^_^
Once you start sniping, you become all but invisible.

RumpinRufus |

So if I understand correctly, a stealthing creature still has to hit normal AC (not flat-footed AC) unless the target is flat-footed? It's only if they're invisible that they can hit flat-footed AC?
Because otherwise the fighter FCB for kobolds would be quite nice (1/2 level to damage.) Fighter would also be able to actually do damage even while having two feat slots eaten up by sniping feats.

My Self |
Oh, turns out also the stealth skill unlock gives you a reduced penalty to stealth when sniping. So any combination of Expert Sniper (DTT), Signature Skill (Stealth) (PFU), Stealthy Sniper (APG), Kobold Sniper (ARG) should give you a -0 snipe penalty, except for Stealthy Sniper+Kobold Sniper, which doesn't work.
In that case, a 5th level Goblin Unchained Rogue (Sniper) sniper could become one of the more dangerous enemies of its level.