If both carry the spec for your car, then the cheaper one.
Since Napa is cheaper and from an established manufacturer (Valvoline) then that's even better.
If you are not staying within the manufacturer OCI, then more research is needed.
By going synthetic, staying within oci and having an oil in spec, you've already given yourself the biggest advantage. Different brands on a new car won't matter much unless you want to achieve something outside the norm.