If weight, size and money are not factors then f2.8 version.
If any one of those 3 is concern then f4 becomes a good option.
Also if you don't need f2.8 then f4 is pretty good tbh.
Personally I prefer having faster primes and slower zooms. So f1.8 UWA primes like Sony 14mm or viltrox 16mm. That gives me the most light when shooting the night sky. For all my other uses I can easily shot f4.
The way i see it primes are best for speed and zooms are best for versatility. Trying to mix the two and you get a large expensive lens that's a compromise in all areas (speed, size, weight, cost, zoom range etc)