I personally prefer the Mandolorian disntigrators with pinpint scopes mandolorian chambers and ryth cell (i think that's the one that gives masive criticals. Along wiht these guns I use sniper shot and sometimes rapid fire.
If your going as an assasin then you should start in it's preliminary proffesion of sentinel. You will git the skills requied to succesfully sneek, plant traps, and sabotage the enemy.
one benifit of being a gardian-assasin, as i found out in k1, sneek attack damage is added to force jump dammage.