I'm going to be going the "switch on the dash" route as well. I'm going to be mounting a pair of rectangular fog lights on the hitch of my wagon to serve as backup lights.
I'm not going to swear to it, but you might be able to get another set of taillights, mount them below the factory ones, and just replace the lenses with a clear ones. That, of course, hinges upon being able to find clear lenses in the right size.
You could also build or buy lightboxes to fit whatever bulbs you want, either one of each or two part bulbs like these
http://www.easternmarine.com/Bargman-Se ... 42-84-414/ .
I've also seen all-in-one trailer lights installed on the sides of the bed, like these
http://www.easternmarine.com/Universal- ... ight-4027/
Somewhere I've seen a pickup build without a rear bumper, I'm not even sure it was a Willys at this point, where they installed a set of square lights (something like these if I'm remembering correctly
http://www.easternmarine.com/Bargman-LE ... 47-84-009/ ) in the rear crossmember of the bed below the tailgate.
If you're planning on keeping your bumper it wouldn't be hard to install them in that, or use CJ marker lights like are on the tailgate of GreenMtnMan's Wagon's tailgate, or even just a simple 2" marker light like these
http://www.iowa80.com/DirectionsWEB/web ... rker+Light if they're enough for the inspection.
Does Canada not have grandfather laws concerning older vehicles? In Pennsylvania at least, we're not required to have any equipment that didn't come standard at the time. i.e. one tail light and no seatbelt in a '51 wagon is fine, even though I won't be leaving it that way.