Hey dude!👍🏽
You can always get this one which is used by many of us in UK
https://hyoriders.club/shop/
Then ill simply get supplier to send a 650 version.
If not, depending on your regrec plug type (some reg recs have split plugs.)
Anyways
You may also consider
Electrosport for 650 and i believe electrosport still make stators for the hyosung also.
Be a good idea to browse the TECH section of this website for 650 manuals. Test your stator with a meter to make sure its operating withing spec
In US i believe there is a supplier that stocks shingden regulators but some may need some wire mods to mix with hyo wires (if they dont already have a conversion kit)
Yes R1 seems common for 650 but some reg recs may be china copies so lifespan is wild on those.
Hope this info helps!