There are two things to look for if you want a quick upgrade, an expanding company with pilot turnover will get you into the left seat a lot quicker than a mature legacy airline where everyone stays until they retire.
Alliance is more established and you prefer their base, however the type rating is less useful than the other two.
Bonza would be a bit of a gamble as a new start up but if it works out you could be right place at the right time, similar to the pilots who joined Virgin back in the early 2000s got a quick upgrade and are now B737 Captains living in Brisbane.
REX is more established and should be a bit more stable and if you weren’t planning on staying long term would be okay for a few years to build up the hours.
You’re lucky to have three job offers, back in the 1990s you were lucky to get one and had to grab what ever was going. At the end of the day it’s a lotto as to which will have the best outcome. I went overseas in the early 2000s and had three possible employers at the time, I simply took the first one that offered me a job. Luckily it was the right choice as they were taken over by a major airline and I’m much better off than I would have been with either of the others.