Stylebee just did an AH-MAZING formal-wear round-up (so many hyphens) that made me think of you:

Lots of eye candy, and lots of versatile styles that can dress up or down.

La Pedestrienne, I'll definitely be digging into that in depth when I'm ready to start looking for more pieces. Thank you!

The pants are great. I have a silk brocade top and pants outfit that I wear for fancier things. Should be quite nice for a wedding.

A good find, Cindy! I really like this one for you.

OMG, LOVE the blue pants and hope they work!! I would definitely wear those.

Love the blue pants, too. And hope you'll go for a non-black outfit or at least a non-black top. Remember: You will be dressing for a WEDDING. A SUMMER WEDDING. In HOT AUGUST.

I love the blue pants, too, Cindy--and your own enthusiasm for them is key. I think they would be gorgeous with a black lace top--there are so many pretty ones out there now--in whatever style flatters you most. Get the pants, and take them (and dressy shoes) with you shopping for the top, so you can get a good idea of the look. I wore a very similar outfit to a dressy cocktail party once (with black heels and vintage blue rhinestone earrings) and received many compliments. And although you have a very casual lifestyle, I think you'll find that you get more use out of these items than you might expect. I've worn the black lace top with slim cropped white cotton pants in August, and with jeans and a black leather jacket in March. I also want to say that a lot of personal history comes through your search for this outfit, and I wish you the very best. Weddings are high-emotion times for families and friends, and can be a strain on everybody. Your own well-deserved self-confidence (because your mother is right--you do know how to do this, and you will) will be a gift to your sister, who is probably feeling a bit stressed and vulnerable as the wedding approaches.