I need to buy flat glass power window kits for my 1937 Cadillac LaSalle.

The differences in price are immense but they all seem to utilize the same basic design. What makes one better than another? Is one easier to install? Is there a huge difference in the quality of the motors?

Any advice would be appreciated. This is a low buck build and these power windows are poised to be my most expensive purchase since buying the car and a donor Suburban.

Thank you