These are many folks' Go-To Guys. https://www.coxandturner.co.uk/piston-rings/These guys toohttps://www.fwthornton.co.uk/piston-ring-sets-l
G'day Tim.You will need to know the bore size, ring thickness and radial depth. Radial depth is most important. Cox & Turner sound good. I don't know of anyone down here.Cheers