On my last kayak I used a 4 inch brush. I built 5 strippers so far and tried all the mentioned methods. I got my best fill with no drips and only two coats after wetout. When the second fill coat was done, it looked like it was varnished - perfect - no drips etc. A wet sanding with 220 got me into varnishing with 320 between varnish coats.

The best way is what works for you.