Guests often ask us what depth finder they should bring up on their trip to the lodge or outposts. For a long time we recommend Humminbird portables, but recently we've been using and recommending the Garmin portables. For about the same price, you get a color screen plus GPS. While these units don't come with maps, our lakes aren't mapped anyway. The Garmin has been easy to use and good on battery life. The one we'd recommend is the Garmin Striker 4 portable, which can be found for around $200 at your favorite fishing store or a little cheaper on Amazon. The menus are easy to navigate and it does everything you'll need on your Canadian adventure.
Now if you want to spend more money, the Humminbird Helix 5 or 7 with the side imaging is the way to go. I wouldn't suggest that unless you're going to be using it back home on your local lakes. Of course, you'd have to set it up for portable use (battery, mount, transducer suction cup or clamp setup). Side imaging is cool to look at, but you really don't need it on our lakes.