The best parts for window regulators

I am now on the inside of my sons 66 cuda. I cannot seem to adjust the windows correctly to fit tight. I took the door pannels apart and noticed that the bushings were either gone or so bad there is play in them. Long story short....lol.
Where and who has the best regualtor parts to fix them? I ordered what was listed a bushing and it do not fit. The one missing is the very bottom that pushes the window up.

Thanks
E