Here's the list
96 points
Soontir Fel - Push the Limits, RGT, Autothrusters, Shield Upgrade
Whisper - Vet Instincts, Fire-Control System, Adv Cloaking Device
Omicron Group Pilot
Normally I always run Engine on my Lambda, but I've found that with this list, my opponent's spend so much time chasing Soontir and Whisper around that my Lambda never needs to boost to get back in the fight, he can just sit back for several turns and shoot into the barrel of fish that Soontir and Whisper tend to create (or he gets focused down and dies in 2 turns).
So I upgraded Soontir's Stealth Device to a shield, and now I have 3 points to spend to stay at 99 for initiative. Despite owning a Lambda since it first came out, I was somewhat surprised at the wealth of decent upgrades the Shuttle is able to take at 3 points. Here's what I've narrowed it down to.
Advanced Sensors - Allows my Lambda to keep his action even when he has to do a full stop or a hard turn, or when he would bump.
Fire-Control System - Slightly better action economy then AdvS in that it can give me a second action on turns that I'm not stressed, but it's less flexible than AdvS. Also contributes to a better initiative bid at 98 total.
Accuracy Corrector - Has a similar effect to Fire-Control System in that it stabilizes my attacks on turns when I am stressed, with more flexibility on when it can be used but with a cap on how much damage I can deal and is less effective with range 1 attacks.
Ion Cannon - Can make Soontir and Whisper's jobs easier when it hits something, but won't be very effective on turns when the Lambda is stressed. Also probably a poor choice against large ships.
Darth Vader - He's popular on the shuttle for a reason, usually to make up for lost attacks in the late game and allowing him to take advantage of usually being ignored early in the game to ramp up the shuttle's damage output at the expense of longevity. I've noticed with this list that the shuttle is usually able to stay in the fight for a long time thanks to Whisper and Soontir, so Vader loses some of his appeal, but he's still a very good option.
Mara Jade - This is a really interesting upgrade for a Lambda, it doesn't do what you normally want stress upgrades to do, which is stop enemies from taking actions, but instead it forces every enemy ship near the Lambda to fly like a Lambda, slow whites, fast reds, no k-turns, which synergizes well with both the other ships and the Lambda itself. It's interesting, but also very situational.
Tactician - The more traditional stress option that can potentially double-stress PTL users and can stress ships from the Lambda's favorite range band of 2, though it's very difficult to control range with this kind of ship and the opponent would pretty much have to walk into this. I think Mara Jade is just as situational but easier to control and gives you more bang for your buck by potentially stressing multiple ships.
So what do you think is the best upgrade for this list and why?