Need wedding day undergarment advice...thanks!

I had a corset-type dress and the woman at Kleinfeld's suggested that I wear a corset underneath. I did... it was a fairly plain corset, so there were no bumps or anything.

My advise would be to ask the woman at your fitting what she thinks. Maybe they have things in the store that you could try on with your dress... you know, so you don't waste your money and buy something that's completely wrong...

I say go w/a plain corset then, and depending on the way the dress falls is whether you get one that goes to the waist or to the hip.
I wore mine to the waist then put flesh tone stockings over it, so the white line wouldn't show through the dress

Blums in Patchogue (Main Street) has a huge selection of undergarments and very good service. I described my dress and what I had in mind and the sales woman gave me tons to try on! You may be able to get some ideas there...
They also have a great selection of bathing suits and cruise wear too.