CPU choice input please

Hi, I’m in the process of building my first pc and wanted to ask opinions regarding a choice between 3 cpus.

7 7700 $459 AUD (pcpartpicker guess)

7 7700x $396 AUD (same)

7 9700x $454 AUD (same again)

Now, price is far from my only metric, I want to learn my own “benchmark” as in what I’ll accept as up to par with my preferences for clarity with future upgrades, as such, if the learning experience is worth it, I’ll chuck an extra $50 on a slightly older part.

Also, I’m a little confused on whether ZEN 4 or 5 really matters at all. I’ve read a few AI overviews on searches, but I’m inclined to not believe it at face value due to past experience. In particular, if I buy a ZEN 4 cpu, will upgrading to ZEN 5 possibly require upgrading other parts like gpu or mobo? Or was ai correct in telling me the only thing I’d need to do would be likely updating bios?

TIA <3