Thank you both for the responses.

We are going to go next weekend, weather permitting. I'm quite excited, I've had him in a canoe before and he loved that, and he's tickled about the idea of camping with me.

You've both reinforced that the Bradford to Burlingame seems like the obvious easy choice, not too long, no portages, flat water, and from what I've seen the sites look nice and there's enough that capacity won't be an issue, especially this time of year.