I have them cut at the company noted below.
We buy in large amounts when ever possible as the price drops, especially after 25 of a size.
They have been very good to deal with and will continue to do business with them
let me know if you would like some , if you are using standard sizes, bottom weighted you can add them to my order. We could combine and the price will drop drastically.
For my personal work, i have them cut at lightimpressions.
We tried cutting some 8ply board just for fun, and it just isn't worth the problems.