The Sepaq site "streamlined" away all the useful circuit info. I have a link to a French-language pdf of detailed circuit info, but that seems to be dead now too! If you're interested in the file, send me a DM and I can pass it along. I'd give them a call as I'm not sure what the booking policy is this year now that Sepaq has taken over. Last year, you called them three days prior to book your circuit--not earlier. They have many circuits and don't over book them, so you should be OK getting permits any time of their annoyingly short paddling season.
Papineau-Labelle does not do any advance booking, from what I understand, which is great if you're OK with spontaneity. I've been meaning to get there--I hear it's a lovely park and would be well suited for what you want to do. Here's their paddling map:
https://www.sepaq.com/resources/docs/rf ... amping.pdfLa Mauricie is a pretty park, but was near impossible to book last year due to high interest. Haven't checked this year. This park would be the busiest of these three. I'd focus on the other two.