I think I am going with this build.
Reasoning:
I am choosing Luck as dump stat and going for sniper build.
Diplomat - is basically 2 free stats because you will at most be using one or two combat skills so -10 to all combat doesn't matter much. +20 Speech is useful. Sequence loss if offset by high attention.
Unlucky Optimist - since I am dumping Luck and not going for crit, any further loss in luck makes no difference and you essentially just get free stats.
7 Str because you get +1 Str helmet and max needed Str for sniper rifles is 8.
6 Dex because you only get 1 Ap per two stats. So it is best to either go 4 or 6.