Been working on the ideal sniper build myself. I don't care for the rogue sniper archetype, since Far shot, and sniper goggles is superior I feel. Not sure if you're trying to stay core rules, but if you're using the D20PFSRD, I would like people's input on my idea.
How effective would taking the Ki Pool Rogue Talent, maximize Dex, then Wisdom, then use one more Rogue talent to get the Vanishing Trick Ninja talent, then at 10th level get the invisible blade ninja trick. This would be effective, if a little limited by ki points to get ranged SA.