Updating T3i - recommendations

[AnnaRamos]

I have a 10-year-old Canon Rebel T3i with a 100mm macro lens and a couple of Canon Speedlite 270EX II. However, I'm interested in upgrading to a newer version. I believe I want to switch to a mirrorless and full-frame camera. 

Can you suggest any models that would be a good fit for me? Also, I'm not sure if getting an adaptor for the lens would be worth it, or if it's better to change the whole system. What do you think?

[AnnaRamos]

Thank you for your recommendations.

I have a lighting set up, in this case, I don't really need extra flashes. However, I also need flashes to some pictures in the dental chair.