Yep R1 coils would also work. Only ones to avoid would be the earlier R6 coils which were CDI, and have a lower primary resistance. You'll be looking for something with a primary resistance around 1.19 to 1.61, so when it's wired up in series it'll be closer to what the ECU is used to seeing, and won't cause any issues with the transistors. MT07, MT09, FJR1300 and R1 coils are safe, but if you can find out the primary resistance then you'll know for sure if it's suitable.. Not sure about other brands.
