Congratulations! I also chose to have a destination wedding for the same reasons. I am getting married the day before you at Dreams Cancun. All that I've done so far other than rings, attire, and invites is the OOT bags. I've also looked into bringing some things down to make my own centerpieces, because I don't think it is worth it to spend the $$, but thats just my opinion.
Good luck and happy planning!