When you say "a 520" you mean boards with the a520 chipset..?
If so the a520 doesn't support the 3200G. From a quick search, if set on the 3200G..? You'll probably be best with a MB using the B450M chipset. The 2 Asus & 2 Gigabyte boards I checked both support the 3200G with integrated graphics.
Here is an Asus MATX suitable one.
https://www.asus.com/au/Motherboards/PRIME-B450M-A/
Just depends also on case choice as to form factor size etc.
** Main thing to check us the manufacturers supported CPUs list but all the B450M's I looked at where fine.