Girl.
I wouldn't know how to raise a boy properly. I've not had the typical experience of boys. I wouldn't know how to give him good advice about success with girls (i've had literal 0 success, I am KHHV), or advice in case he gets bullied.
I don't know any sports, I have a subhuman physique, I couldn't play any sports with him, I DON'T EVEN KNOW HOW TO RIDE A BIKE, I COULDN'T TEACH MY SON TO RIDE A BIKE
I am not a man, I'm 31 yo and yet I still look like a teen. I have thin wrists, narrow shoulders, thin arms, I get frame mogged even by most young women.
With a daughter, at least my girlfriend (assuming she would be a typical low tier becky) would know normal girl stuff.
Not to mention, girls have a better life quality from every single metric. They have better job opportunities, more support in society, easier love lives, easier EVERYTHING.