I'm currently in my 2nd year for 309A ICI through the local (IBEW 353). I do commercial and tenant work.
I hate to be the bearer of bad news, but the consensus at the JAC and union is that the pre-apprenticeship courses are a waste of money and more importantly time.
If you are in Toronto you should try applying directly to the JAC, or whatever education council is set up in your area.
Toronto JAC is doing their intake in March actually. The timelines are very strict, so make sure you have your paperwork in order if you plan to apply. You need certain high school upper level math, English and physics. The odds are not horrible. When I applied in 2014 there were about 1500 applicants and about a 100 spots. So it is not horrendous.
If you want to be a civilian electrician, you should probably apply directly, without going trough the forces.
If you want to be a forces electrician, you should probably apply for forces electrician.
Don't waste time finding out down the line that your training is not transferable.
You will also probably make a whole lot more doing civilian electrical.
I grossed 60K in my first year with all the double time.
Full journeymen were raking in 120-150K that year.
So if money is what your after, civilian electrician may be a better bet.
When they built the gas power plant downtown they had 60 hour weeks; a large chunk of that was double time. So people did very well.
Linemen are also not a compulsory trade in Ontario, while low voltage (up to 600 volts) electrician is. So if distribution technician is the forces equivalent of lineman, then there are realities to consider.
You can also try the Power workers union. I have no idea about them, but they do have an application process on their website.