Honestly, be careful with the bigger monitors if you're doing sports. In my experience, even high-end ones can feel reallyyy top-heavy on a cage ...
For Canon EOS R3, Canon RF 85mm f/1.2L USM is an excellent choice. The optical stabilization is very good The fast autofocus makes everything feel res...
I have a different experience with Canon RF 50mm f/1.8 STM. For me it was too expensive for what it offers.