I thought with the typical destination wedding, there were VERY few people actually there (i.e. an attendant or two on each side and possibly the immediate family) and you just sent out announcements of your marriage and possibly had a reception around your home after it was all over and done with. I guess I just don't move in classy enough circles.
PA - don't include registry info in your wedding invite. People will know to look in the stores and if they can't find it, they'll call your or his parents and ask. If they don't, well, you'll just get lots of towels and you always need towels.
As for the donation to the foundation - I wouldn't go there because unless you know everyone you're inviting espouses the same causes as you do it could get VERY sticky. You might think (for example) Animal Friends is perfectly safe, but you never know who had a bad experience with them or something.