To echo gearwdownflaps30, apply EVERYWHERE. Learn where their bases are and which would have the easiest commutes.

Even though you're telling them you'll have 1500 by the end of July my guess is you'll get a lot more feedback from recruiters when you're AirlineApps account actually says 1500.

I'll let some actual Waterski folks comment on the upgrade times, but from what I know for a small group of folks hired at exactly the right time a very short upgrade is certainly possible as they add airframes and existing pilots move on to other positions. That said, the later it gets in a given hiring cycle the longer the upgrade has the potential to be.