It was 90 degrees here today already. I'm getting nervous about dressing for the heat!

I have never worn a dress like this before, but Angie suggested I try a more structured dress, and I think this might fit the bill! I like that it has the notch at the neckline - is the white cami okay? I also like the A-line. I know Angie approves of sleeveless, although I am not quite used to that yet. For some reason, I feel flats work better with the leggings. The only flats I own are these sandals. I think they're okay, but would a ballet flat look better?
http://i387.photobucket.com/al.....1090-1.jpg

I also tried it with my white denim jacket. Does the jacket look too big/bulky? Should I look for something more cropped? (Or maybe get this one tailored?)
http://i387.photobucket.com/al.....G_1092.jpg

Thanks in advance for any and all suggestions! (And if you hate it, please tell me!)