Instead of limiting yourself to one piece be open to all the other lingerie alternatives on offer. A corset may not necessary be the right look for you, a body shaper will provide more of an effect. A lot of dresses will already have the corset and bra already built into it however if not then be careful to consider the right bra  and more importantly one that fits.

I also strongly recommend wearing the bridal lingerie for a trial run before hand. I bought a strapless bra for my wedding dress and more or less spent the whole day trying to keep it up. Other bras such as the stick on adhesive bras can loosen with sweat, so as you can see a trial run is essential.