They are both really sexy.You must have a gorgeous body, if you are seriously looking at either.I was originally on the fence, but am going to go with some of the other gals,and their opinions, and say that it may be just a tad beyond your age group,for the moment. Opt instead fr something just a little longer in length.
I like the open back of the first one, but I don't like the jeweled detailing, or the open sleeves.
I like the second one best. It's more my style. But it's also a sweater dress. Sweater dresses typically look best on girls with very little body fat, or else girls who are extremely well-proportioned so that a body-hugging dress like that doesn't hug the wrong parts a little too much, haha. SO regardless, though very much my style, it wouldn't be a dress that I could pull off. =P