External coil question

I have a 74 GPX338, I need to change coils as the old ones have some cuts and abrasions on the wire. My question is: Are both coils the same? Yamaha lists 2 different part #'s for the left and right coils. Also, is there preferred manufacturer, spi or someone else?

They are the same except for wire color and plug wire length. I would find a used one before I would consider one from China. I have heard a few bad stories about them as well as having them myself.