Huh centric spacers smaller OD

[JROD88]

I am in the process of putting c4 corvette sawblades(go hate somewhere else) I don't want to run adapters. I would like to get 20mm spacers with a smaller outer diameter, does anyone know where I could buy this exact product? I know I can buy normal hubcentric spacers and mill them down, I can also get the wheels milled to the 72.56 that I need, I have been quoted at 45 per wheel, but I would like to keep the wheels original.