As the title says.
The three original Systems are still available, but I only see conversation about the two most recent for the TIE/x1.
Cozlet: At the start of the End phase, you may spend a target lock you have on an enemy ship to flip 1 random facedown Damage card assigned to it faceup.
Though the Accuracy Corrector is technically superior in damage potential, a Fire-Control System has obvious synergy with the pilot ability.
Alozen: At the start of the Combat phase, you may acquire a target lock on an enemy ship at Range 1.
With Damage buff taken care of, we can concentrate on getting him into Range 1, and getting him to survive it.
His ability gives Advanced Sensor shenanigans their best chance on the craft, both for the mobility to get into Range 1 in the first place, and the avoidance of collisions (or the action-loss therein) from the knife-fight.
Sensor Jammer is also a great option for improving his damage further, as it means that any ship shooting at him wants to spend their action offensively. It pairs wonderfully with Opportunist as well, giving him that bonus die.
Strom: Enemy ships at Range 1 cannot add their range combat bonus when attacking.
Sensor Jammer is amazing on him. You've already reduced their damage, and you're likely to be flying alongside Carnor Jax.
Stele: When your attack deals a faceup Damage card to the defender, instead draw 3 Damage cards, choose 1 to deal, and discard the others.
This is a Fire-Control System only because Adv. Targeting Computer isn't allowed in my scenario. Target-Locks turn your ability to roll a [KABLAM] from 1/8 of each die to 3/16, so it's technically a boost to his ability.
Eclipse: When you reveal your maneuver, you may increase or decrease its speed by 1 (to a minimum of 1).
Lady really wants a damage buff to take advantage of her insane mobility.
Advanced Sensors to make her even crazier than old-school Echo? With such a low primary attack, she'd be playing a very defensive game, and you'd basically be investing 1/3 of your fleet in a game of "I don't need this to deal damage, and you will never be able to damage this".
FCS gives her a damage boost, but she really really wants the two that I've eleminated in the conceit of the post. I'll be using AC on her, so I don't have to forecast my target or spend an action offensively.
Vader: During your "Perform Action" step, you may perform 2 actions.
Advanced Sensors are out, as they work against his ability.
FCS isn't as good on him as the two I've disallowed, but is still very playable.
Sensor Jammer... is really quite nice. Those two actions can be spent offensively, defensively, or for mobility, so this is acting as a boost to the rest of his fleet.