Hi,
I suggest you talk with your counselor at your school about the factors you'd like to take into consideration. My counselor personally advised me to think about the cegep in which you'll be the most motivated to study in. You're going to have the opportunity to attend to open houses and even classes (student for a day) so it should give you a good idea of the environments you'd feel comfortable in.
Also, don't worry too much about seeing the same faces over again in Vanier. A lot of people from my HS wanted to go to JAC. Some didn't get accepted after 2 rounds. Many are in different programs. The people who are in Science program (20+) barely have a single mutual teacher. Very different schedules and breaks. Also, people who applied because they didn't care about being surrounded by the same classmates forever are usually very friendly students in my school that I personally wouldn't mind seeing for two more years. So there's that. It's a salty schoolmate filter.
I come from a french HS but I still applied to an English college just because I feel a lot more comfortable expressing myself orally in English.
And yes, go to the nearest cegep.