Thanks for the response Buhgaboo. I did end up emailing the seller and this is what they said:
"Hey Brad,
Thanks for reaching out, and great bike! The M2, M6, and M7 designations are European TUV certifications. I don’t have a ton of information about what that means in Europe, but I do know that we don’t use the TUV system here and those designations should map back to the same part number on our USA website. You can match the part numbers or click into a product description and use the “bike check” feature on the product page to confirm fitment. Here are links to the items that came up in my search, in case it’s helpful to double check:"