Cartridge upgrades for Technics SL-1200MK2?

Just bought a Technics SL-1200MK2 and paired it up with a Shure M97XE and it sounds absolutely wonderful! Just thinking ahead here .... what cartridges should I be considering down the road. I listen primarily to Classical and Jazz and my main amplification is tube- based. I prefer a warmer sound rather than a forward in-your-face presentation. I have a feeling the Technics will respond nicely to cartridge upgrades. I am shocked at how good this unit plays. Puts my former high quality belt drives to shame!

Regards,

John