Manual have more better gear ratio some comes with LSD. Auto b16a have milder camshaft and lower rpm gear change. U can use manual cam or type r cam and piston with ur auto b16a for better acceleration but performance still cant compare to a stock b16a manual.
I suggest if u wanna keep auto just change to b20b/b20z block with some bolt on mod. If u want power and reliable then go for b16b or b18cr halfcut comfirm puas!