From an Admech archetypes I would see:
Branch 1: Skitarii (Ranged focused)
Blitz: Phosphor Blast Pistol
Phosphor Pistol that has an AoE that augment weak point damage on enemies in the AoE.
Gain back ammo from normal ammo pack instead of grenade boxes
Ability:
Ranged stance, instead of buffing speed or giving aiming aids, would increase weapon power and give rad DoT to them.
Branch 2: Sicarian
Blitz: Arc Grenades
Grenades that throw bolts of electricity, which will jump from armoured enemy to armoured enemy
Ability: Mindscrambler Protocol
Short cooldown/multi charge shout that will stagger enemy and increase weak point damage they take.
Branch 3:
Blitz: Guardian Skull
Throw up a Servo Skull armed with a Stubber, it will then follow you around while shooting targets that you ping or elites/special that are close by
Ability: Servo Thrall
Summon a pair of melee Servitor equiped with Servo Claws, can be upgraded to Heavy Stubber Servitor or Power Claw Servitor