My friend also insists that Ortofon RMG 309 tonearm and the original SPU Silver Meister (not MKii) are best for Garrard and Thorens.
Ortofon is not the best tonearm and SPU is not the best cartridge, there are many more classic high mass tonearms and low compliance cartridges.
If you want something ultra high-end then Reed 3P is perfect for Garrard and Thorens turntables (it can be used with modern cartridges).
Anyway, this is a personal choice. Why do you want some boby else to tell you what's the best ?