Going away dress... part 2

I don't know what to do about a going away dress! I was so convinced last week that I definitely wanted to do it, but now I'm having second thoughts. I love my wedding dress and I definitely don't want to waste money on a second dress/outfit if it's not necessary. So, I haven't made a final decision about what I'll be wearing when we leave the reception... But, I have figured out which of the ones in the earlier post was my favorite. I think that I like #5, the strapless, cotton sateen dress, the best. Here's a picture of me wearing the same dress in green.

So, I guess I'll keep thinking about it. If I do go this route, I might get a cute hair piece or birdcage veil to make it look a little fancier. I don't think that my fiance will change out of his tux, so I don't want to look too casual. What do you think I should do/wear?

PS... my first wedding dress fitting is TOMORROW!! eek!