Nate, I'm curious--what shortcoming did you find with the other pieces you tried? I have installed generic 9/16" channel appropriate for the glass thickness, but Covid has kept me from the car for a year next week and my only worry is whether the glass actually moves well in the frame...!
Great to see you are making such progress...can't wait to see yours finished (either! maybe 2021 will be a great year for both our cars...!) Lee