As with pretty much everything, a lot comes down to trial and error and personal preference. This may sound like a cop out answer, but there really is no substitute for trying things out for yourself once you've narrowed some of the choices down (as you have).
Personally, I have found that rosin responds more to temperature changes than humidity, but the hair responds more to humidity changes. High humidity can make the hair very slippery, which might require more rosin, or possibly stickier rosin. But stickier rosin will turn to goo and gum up your hair (and sound terrible) if it is also hot.
I'd keep a few different types on hand so you can adapt to different conditions. A cake of rosin is pretty cheap (relatively) and if you make the wrong choice all you have to do is keep playing to the rosin you don't like off the hair
Maybe some of the guys from the southeast coast of the US could comment on how they deal with the combination of heat and humidity (here I have humidity but very little heat
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