I know exactly how you feel. My hair is considered the "good" texture hair too. But, when I was in Jamaica in January my hair frizzed within 10 minutes of being outside.
I would do a trial run for sure ahead of time. Now, since it's Jamaica they will most likely be familiar with black hair, but might not be totally familiar with silkier "good" ethnic hair. Hope that makes sense. I think I'm going to bring my own oil with me too, because it's fantastic and I'm sure it's better than what they have. When I was there in January the best oil I could find was Pink Oil.
I'm also going to get fusion extensions put in before the wedding and wear my hair half up half down. So hopefully most of my real hair will be protected from the humidity in the updo.
On another note, wow you're less than a month away! Are you getting excited?