Activity for Lannet

Should I keep my hair style (photo 1?)Or change it to the 2nd photo

Don’t know how I should do my hair to match best with my wedding dress. Should I do up or down or both ?

I'm in love with my dress ( first photo) but have been thinking about the neckline! I am dying to know if it's possible to do a deep plunging sweetheart to show a bit more cleavage like the 2nd photo. Whats your opinion?