Hi Kelly Ann,
Ooh...I love tight corsets. As I'm sure you know, they give you more of a feminine shape and make you look slimmer. I have a custom made one that I bought from a great UK store called Axfords.
http://www.axfords.com/Site/index.cfm
I'm lucky enough to have Marla help me with the laces. She usually laces me as tight as she can, which usually means it's fully closed which gives me about a 26 and a half inch waist.