First thing I'd do is call my resort directly and tell them what you want done and see how they suggest you do it. Since your room is assigned upon check in, I don't see how it can be there waiting in your room if you go directly to your room after check in. If you're like the rest of us and run off playing before you hit your room, you are in luck!
Next thing, yes sending yourself a package is cheaper, but not nearly as fun. THere are a ton of other sights to choose from, 800flowers, proflowers, edible arrangements (These are GREAT fruit cut into shapes and some of them dipped in CHOCOLATE! I'm doing this for my Disneyland trip in February for my friends birthday), cookie bouquets, and this one I recently found
http://www.designityourselfgiftbaskets.com/snack-gift-baskets-snack-gifts.htm
and another one I have used is:
http://www.hometownfavorites.com/ These guys have fun hard to find things. Gift boxes and baskets.
And that's my two cents