Look into the resort photographer and see if you like the portfolio. I'm doing the same thing in May and I found that most of these resort "photographers" are just locals with SLR cameras and no special training. On top of that it often costs around $1200 for an hour. I've been to two destination weddings and both couples just had a friend or relative take pictures, and they both just used auto settings. In the end they weren't professional pics but pictures none the less which seemed good enough for them.
The real professionals don't live on the beach, you gotta fly them down which gets fairly expensive.
Personally I would go ahead with your plan, get yourself a decent camera and lens kit combo, practice, and shoot in raw. As long as the person can frame the picture and focus correctly you should be OK, later on you can add those typical wedding effects with photoshop. There's also lots of wedding photography tips online that would be worth checking out.
http://digital-photography-school.co...-photographers
http://digital-photography-school.co...tography-shots
http://digital-photography-school.co...-photographers
http://digital-photography-school.com/weddingbeginners
http://digital-photography-school.co...-wedding-shots
http://digital-photography-school.co...mposition-tips
and so on
Chances are if you're the destination wedding couple you're not as picky as the typical couple. Ask yourself what you want from your wedding pictures, chances are you don't need a professional, just a guy with a camera
Congrats BTW!