http://xwing-builder.co.uk/view/657165/kanan-and-the-rebeletts

Will this work without Biggs ?

Try and see. Still Rebel tie too new to say for sure. Probably VCX will go down a lot faster with no biggs.

Well I figured Rex after first round is going to be such a pain combined with Kanan's ability, Rex will be the main target. Rex though will evade when ever he can and kanans ability will make him pretty hard to kill easily. Ahsoka ability will mean Kanan can reposition before combat and do an action if needed

I think you are running into cost issues. I would rather take Rec Spec than Jyn given how many 2-3 ship builds are in the meta at the moment. EI could be handy but also lands Kanan with Stress which is not great news for him. He could get a better effect by Ahsoka spending a Focus token on him so he can Boost at PS12.

If I am investing in a Shuttle then I would prefer to maximise the bang for buck with a better turret (ideally TLT). ABT works best either as a deterrent on low PS ships or if you have some means of using aggressively to hunt down slippery aces. I think the list tries to do too much but does not do any of it well enough.