Mainly classical and jazz? And you got a Thorens turntable? And 78 records?
Well, as I see it there is only one solution...
the Ortofon OM 78 cartridge.
I don't have personal experience with the OM 78 cartridge, but I have experience of other versions in the OM serie and they work very nice with classical and jazz. Ortofon also works very nice with Thorens turntables. (many Thorens were bundled with Ortofons in the past).