Which school is better for you?
I suggest that you visit both schools to see which is better for you.
NYAC: is not for someone like you. It's by invite. You need to know someone who goes there.
Oishi and KBI NYC are both excellent schools, and very highly regarded. Both schools participate in 2x/year Hudson Judo Promotionals, along with other judo schools from NY and NJ. There, you see various players from both clubs participating, as well as senseis from both schools.
For Oishi: Oishi Sensei teaches M, W, F, Sat classes (both day and evenings). This class is 20-30 min juno kata (streching), light warm ups, 20-25 min newaza, uchikomi, and rest randori. Oishi Sensei teaches all classes on these days, and he also plays both newaza and randori with students.
Tuesday and Thursday evening classes are now led by Pernambuco Sensei. This class is usually as follows:
50-60 min newaza
3 newaza techniques drills
uchikomi--line up
some stand up drills
30-40 min randori
Some times, this class starts with stand up randori first.
Both Oishi and Pernambuco senseis are terrific instructors, in dealing with beginners as well as more advanced players.