what's the better between the ryzen 5 7600x and the ryzen 5 9600x?

I'm gonna build myself a new PC in the upcoming months, mostly waiting for the rx 9070 launch or to find a 7900 xtx on sale, and i was scouring the internet to look into what component I could use and I've on an online store in my country that the ryzen 5 7600 and ryzen 5 9600 are very close in price, a measly 20€ difference, so I was wondering if the price stays the same which one would be a better buy? and does the 9600x fits in a b650 mobo or since it's newer does it prefer a more expensive motherboard?