I'm from the Toronto area, and afaik, HS courses are credited the same.
In fact, many grade 10's and 11's take grade 11 and 12 courses during this time, to lighten their workload for the fall and winter semesters.
What type of jobs are you looking to apply for?
If general labour, then they don't care much for what you're taking anyways.
I think the reading lists should be approximately the same, since the curricula are the same throughout the school board anyways.
Feel free to ask more questions. After all, it'll happen alot in English