If you want to use sniper as primary weapon and smg as backup, I'd not use Versatility, but have high perception. Accuracy and damage is much better like this.
Starting base stats: 5, 6, 6, 3, 10, 3, 4, with 3 points to spare. Put more in int if you like crafting, more in con if you like to live, or more in dex/agi if you want relevant traps or mobility feats.
5 str to use snipers
6 dex to save 1 ap/shot from all SMGs, and for general utility
6 agi for Spec Ops, Sprint, decent stealth etc
10+ per for Snipe, damage, accuracy etc
4 int not to suck completely at crafting, hacking etc. (Opinions may vary about this) I'd probably increase this to about 7 eventually.
Lots of Guns, Stealth, Traps, detection, silenced 5mm smg, sniper rifle, you are an assassin. Always plan a way out if you miss a sniper shot.