Painless switch panel?

Has anyone used a Painless switch panel to wire up a drag race car? Thinking about using the #50302 6 switch panel. How much of the original wiring did you keep? I'm thinking neutral safety switch and starter relay can stay, otherwise eliminate all of the 38 year old wiring from the car. Does anybody else make one of these kits? Painless can be a little pricey. Thanks for any replies.