Hello @Neo Chiu and welcome from Virginia. I have not seen an aluminum box on the newer R3s yet but Corbin does make the fiberglass panniers. I suspect that any generic aluminum box with the correct frame mount will work though. I'm sure someone will come along shortly with better answers though.
Welcome from Northern Ontario. Congrats on one fine purchase. Correct me if I'm wrong but your ride looks blue in colour. Is it? I also like the looks of those bags and their location. Do you have a picture of the bags in place without the top bag?
Welcome from Northern Ontario. Congrats on one fine purchase. Correct me if I'm wrong but your ride looks blue in colour. Is it? I also like the looks of those bags and their location. Do you have a picture of the bags in place without the top bag?