3
Besides a better gpu (look out for PCI-e gen difference) I highly recommend a higher refresh rate monitor, e.g. 144 Hz instead of 60 Hz. If you use your pc for gaming, this will make a huge difference in experience.
Also, unless you care about a silent pc or 'cool running' one, I'd wait and see whether you really need to upgrade your PSU when upgrading your GPU, but don't let it exhaust itself