Should i transfer to an All-Boys school or not?

I’ve recently moved from America to New Zealand and i go to Mt. Roskill Grammar school right now. It’s an average school, but nothing compared to the school i went to in America. I’m having a hard time getting used to the Education System and making friends is an issue too, people just act differently here…
But now i’ve got the option to go to a better school Education-wise, because this all boys school (Auckland boys grammar) runs on a system similar to America’s (Cambridge International Examinations) but i dont like the fact that it’s an all boys school.
I’ve grown up with co-ed schools, and also get along better with girls so i REALLY don’t like that idea, but the Education would be so much better there. I’m going into year 12 next year by the way, So just 2 more years of school for me (school is 13 years here)