Everyone has their own preference, but for that hair I’d use a 42 or 43g crown (three barbs). Unless I’m going for really thick hair, I typically root by isolating one hair from the cut end and punching it in.
Anything bigger than 42g tends to leave visible holes in the vinyl for me. (Smaller number = bigger diameter)
Oh! I actually really like these new needles I got called “notched” needles. They have three barbs, but they are staggered along the end rather than all at the tip like crown.