rear shocks on these scoots tend to last a looong time...(see Stig's daily rider scoots, with a...XXL...passenger)
Are yours leaking or are you looking for a performance upgrade? OEM would be my first go to, if replacements are needed. There is not much aftermarket support for Kymcos in the US.
Maybe measure the shock and do a search for matching generic gy6 scooter shocks?