Need To Upgrade my PSU

As per the title, I need to upgrade my PSU. Currently have an issue where it is causing my monitors to go black and for the fans to go crazy. After looking online and running some stress tests it looks like the PCU is the issue.

Currently I have an Aero Cool Integrator 600W. It's roughly 6-7 years old so I need a new one.

I saw the CORSAIR RM750e online, however I'm unsure if that is a better one. What would you all recommend for a better PSU (with a £100 budget)

(Extra context: my friend built my PC for me back in the day and I am not at all tech savvy.)