I suspect you may be referring to broadcloth, which BB does carry. You may want to try a few stores which carry shirts to find the fabric. Once you have identified the fabric, you can then investigate makers.
While I agree with your comment that the jacket is not to be removed and the suspenders not seen, it is fairly commonplace to remove jackets upon entering the office. I will put mine back on for client meetings or to go outside of my building, but do walk around the office without a jacket while wearing suspenders.
I am wearing some suede captoes today I probably purchased 14 years ago. They are not worn with great frequency, but have held up very well for me. I would not hesitate to spend $500 on suede shoes again.