One data point that might help: print out a couple of the dresses and ask your instructor how long it would take for _her_ to make the dress. What I have found is that sewing projects always take longer than I think (even when I factor in that it will take me longer than I think). And you only have 3 weeks to make it. But it is always awesome to make something that has everything you want as opposed to settling for something that has 50 to 75 percent of what you want.

Having said that, out of the selection of dresses you have I really like the If it Ain't Baroque Dress, the Dipped in Champagne Shimmer Dress, and the Vanilla Biscotti Dress. Do you have the option of wearing a sari or salwar kameez?