I highly doubt if we ever did get back in the game (again highly unlikely, a lot more pressing priorities) that we would jump straight into top tier as we would essentially be starting from scratch, learn to crawl before we walk not straight into running so to speak.
Our allies are getting F35s as it is the next logical step for them in their force evolution and they have a benchmark to go off (and operations/requirements to suit), for us putting some unguided rockets onto the T6s will be a major advancement (as primitive as that sounds) so something like F16 will still be a pretty huge leap in our sphere and probably more aligned to what WE would do or more importantly what our govt would be inclined to commit to.
Do not always go off our allies as to what we should or should not have or level of tech required as NZ is vastly different to Oz is different to UK is different to US. We may go on the same ops to do a overall similar job but we also go about and achieve the end result in different ways as well.
In terms of fast jets you just have to compare old 75sqn firstly to our Aus counterparts in a regional context then say to UK/US operational squadrons in a international context for example and think back to what they/we actually did/do and why would this position change? Nothing in our bubble and operational posture or willingness to me screams F35 that could not be equally achieved with F16 or even armed T6 in terms of what we would actually use them for. It more just seems a case of keeping up with the Jonses, state of the art and cutting edge is nothing if there is no willingness to 'use' in the first place, looks good in the hanger but those sleek lines cost in turn.
Anyway if we are requiring F35 to win the fight chances are we are in over our heads to start with.