Choices for first belly-on ring?

I've got an appointment to get my navel pierced on Thursday. I hear that there are a few choices for the first ring you get. Is it true that you have to leave the original one in for a year? Can I still get something that dangles? Do you have to get a ring or a barbell? Which is better? Do they have fancy ones that you can change out the ornament without disrupting the piercing? How much money am I looking at paying? (not that money's an issue, I've got enough saved up, but it'll be goo not to be surprised). Anything you can tell me about what will happen would be great!