bc resident applying for chinese L visa in toronto. also same day?

Im currently a bc resident (ontario birth certificate) now visiting ontario, i am flying to china out of ontario and am hoping to get a visa in toronto. is there any additional requirements for me to do this? also i am staying far from the city, is there any way to get one the same day in the city? or can i mail in my application? im hoping to fly very soon - in 19 days, what are your recommendations? i am staying with my siblings living in china, do i need a invite letter from them, as i do not have hotel reservations? or is my flight details (with return trip) and their home address enough information.