What cartridge/stylus upgrade for Dual 510

Hi everyone, I'm very happy with my Dual 510. Got it running pretty good and all functions do what they should do. I'm using a Dms210 cartridge with a Dn211 stylus. I've been reading about the difference an elliptical stylus can make for the sound quality but I'm a bit lost as to how I should do a possible upgrade and what items to look for. Looking for advice for budget friendly upgrades!