Here's a couple people you can get pricing from:
I had Mary Lou do some cover enhancements & isinglass work for me
Mary Lou Pults @ Stuart Canvas Co
507 East Parkway
Stuart (772) 288-7084
The 3 Ladies @ Hobe Sound Canvas do good work. They did a redo of my T-Top after the Hurricane damage. They also did some custom cushion work for me.
10520 SE Federal Highway # 1
Hobe Sound, FL 33455
Phone (772) 546-8550
Good canvas work is not cheap thou