I also carry one, and sometimes two, canoes on my 2010 Ford Escape. I use the Yakima rack system and had Yakima "Landing Pads" installed near the front of the roof to make a longer spread between the bars to be more suitable for carrying 16' canoes.
For front-end tie-downs I actually went to the trouble to have a custom-made bar machined to attach to the front bumper using existing holes in the bumper. The bar allows standard eye-bolts to be added. After a couple of prototypes I think I've got a nice front-end canoe/kayak tie-down solution for the Ford Escape and had some extras made to see if anyone else would be interested in buying one. You can see my tie-down solution at http://www.hookedonmyescape.com