Backyard Wedding - What to Wear?

One of my best friends from college is getting married in two weeks and ever the last minute shopper I am, I don't have a dress!  The reception is tented in a family members backyard for a chic, intimate celebration and the affair will be anything but casual!  Here are some perfect pastels I'm considering for my besties wedding!  Which is your favorite?

1. Lilac Peter Pan Collar dress from TOPSHOP - a steal at $96 buy here

2. Strapless Arabelle dress from JCrew $250 buy here

3. Alice + Olivia's petal dress $440 buy here

4. TOPSHOP'S tulle skirt dress $140 buy here

5.  My favorite of the bunch, Valentino's strapless bow dress $1,471 (on sale) buy here

6.  Reiss' embroidered dress $298 buy here