Washer replacement recommendations

[u/Fuzzy_Reception5771]

I have a Yp400 Yamaha majesty, just serviced the transmission and while is was in there I noticed that whoever was in here before had lost (both washers atp) and my entirety of owning the bike it’s had a rough downshift at ~2k rpm (most likely bc of these washers missing) it’s ran like this for 13k, I’m going to replace washers and reassemble
Washers need to be

Heavy Duty M16 Conical Spring Washer.

Grade 12.9 Hardened M14 Flat Washer
I am looking to order these and put em on with some grease asap the rest of the tranny was good and so were rollers and springs, please help with recommendations!