7000$ is more than enough...especially with camping.
i guess it depends on how much you throw away towards booze...thats always the killer. money seems to dissapear after a night of drinking (then having to eat after the bar too!)
Anyways if you have any questions, specifically niagara falls/toronto/algonquin,,,,just ask me i can give you better tips closer to your departure date...also just outside the entrance to algonquin park there is a hostel called wolf den backpackers...ive stayed there and really liked it.
Hope you have a good time! Should be hot and muggy in August!