Here is a little list I came up with fiddeling around with the combination of Biggs and Rex:
Biggs Darklighter (25)
R3-A2 (2)
Integrated Astromech (0)
Captain Rex (14)
Airen Cracken (19)
Swarm Tactics (2)
Norra Wexley (29)
Push the Limit (3)
Tail Gunner (2)
R2-D2 (4)
Alliance Overhaul (0)
Total: 100
View in Yet Another Squad Builder
I am not too happy with Cracken, but at least he allows Rex to shoot earlier so you have the attack reduction as soon as possible to protect Biggs. He also allows for self-blocking Rex to keep him close to Bigs while retaining actions.
And there also lies the greatest challenge of the build: Having the TIE not overshoot the rest of the squadron too far while tethered to Biggs. I believe only in practice can this be adequatly assesed.
I'd really love to hear some alternatives for Cracken that I haven't considered, the 4th ship really is not a clear choice.