I buy the aluminum crush washers in bulk and use them on my Valkyrie and VTX. The Valk takes 14mm for the oil drain and the final drive, the VTX takes 12mm for the oil drain and 14mm for the final drive...I also use the same oil filters on all three bikes and get them for a decent price in larger quantities. I bought 100 of the 14 mm for $18 quite a few years ago and have given quite a few away to fellow Valk riders over the years....probably down to 30 or so left which should last my lifetime...
14mm
Honda OEM Parts Part Number: HO-0171876x10 - Direct Line Parts
12mm
Honda OEM Parts Part Number: HO-0171868x10 - Direct Line Parts
filters
Honda Part Number: HO-8597650x10 - Direct Line Parts
Directline honda runs 10% off sales all the time and there is one running through tomorrow. Have to spend $100 for the 10%. No affilitation, just a loyal customer over the past 12 years or so.