I actually called a glass place in town and explained what I wanted for the 9 degree ruler and the guy told me it would cost about $6 so for that one I might get them to cut it for me. They would be very accurate there since they have all the right tools to do it.
The way I did it would be best for a basic square to be honest with you. I will say that I wish I had thought of going to Lowes before I bought the wide ruler for doing my fabric folding - I could have saved myself $10... It's all good. Folding that fabric like that was worth every penny I spent on that wide ruler.
For a wedge ruler I would suggest contacting a glass repair place. Tell them the measurements and see how much they would charge :)