I have yet to get a binder because I pass so well witout it and I havent had the money. Im somewhere between a large B and a C (have yet to measure, will soon tho). Im thinking of a tri-top or maybe something from Les Love Boat. I do want to look nearly completely flat tho.
I just ordered my first binder. So I can't give you any advice as far as that goes. But as for you not having enough money to get one yet, I can suggest to you to look on Amazon for the same binder you want. I found one I wanted to get at Underworks, and then I found that exact same one on Amazon for 30% less money. and then on Amazon I got to read the reviews on it as well. I love Amazon, lol.