the only patches available that I have seen are the ribbed "steps" if you will. I think they come in like 1 foot sections and with no contour. I have had this debate with myself too, based on the money going into the patches, the time and effort to cut out the old and weld in the new, and the time spent making them look nice, I would shop for a decently solid set of used ones, but thats just me, good luck with the project
