Take a look at this beauty with the center medallion of the wedding couple.
http://www.quiltingboard.com/picture...t-t236625.html
If you make the center smaller, and make the signature blocks smaller ... I'm sure you can squeeze 100 of the sig blocks around the center medallion. In fact, here's a link to a sig block that would work. It's 4.5" and these can be arranged in a zig-zag around the medallion. (see pic in post #3 for the signature blocks).
http://www.quiltingboard.com/picture...c-t221233.html