I would say go with the i7-13700k if you really need more cores for video editing and 3d modeling otherwise either one works.

I would recommend a framework laptop with this kind of budget. Linus tech tips is an investor in the company.

It could also just be the silicon lottery. Some people get lucky so there cpu might either overclock better or unvolt better but it could be you aren’t as experienced so you could be doing something wrong.

If price is your problem go with ddr4 but like future proof I think it is better you go with ddr5 you should try to get at least 6000mhz cl36 or cl30 you get better performance.

In terms of motherboard you don’t need a top of the line. You need motherboard under 200 if not under 300 and is z690 or z790 chipset. Make sure it has what you need like WiFi, enough usb ports, or many ever many m.2 slot you need for storage.