AMD recommends a minimum PSU of 800 Watts for a PC using a RX7900XT.
According to Nvidia for the RX4070TI recommends a minimum 700 Watt PSU for your PC.
Since you are getting High power GPU cards plus a powerful Processor I would suggest a minimum PSU of at least 1000 Watts for both to prevent power issues and future proofing your PC for an upgrades in your hardware.
As to which GPU you should purchase depends on what you are planning on using your PC for. Like mainly for gaming or running apps or just normal general use like watching videos or browsing the internet or running regular 3rd party apps that are not the Professional type.