Thanks for the info! I ended up calling CMIPQ first, and they were friendly and could give us an appointment for a Saturday, which meant I didn't have to pull my kid out of school, and I didn't have to miss work, so I just went with them-- glad to hear their prices were good! They charged us 250 CAD for each adult exam, and only $100 for the child's exam (I guess because he didn't need the chest x-ray or the blood test). Everything went smoothly, took about two hours in total.
Now just anxiously waiting whatever are the next steps. We've already submitted our police certificates as part of the application, so I'm hoping there aren't too many more hoops to jump through, and that we're close-ish to the finish line...