I purchased Yakima low rider mounts and the 58" Yakima cross bars. I haul my 14 foot canoe many places. I am sure the 16 footer would be a non issue. As far as visibility, you don't even notice it. It's well above your "road" field of vision.
Yakima part # are;
Low Rider Mount- 8000114
58" Cross Bars- 8000409
Gunwale Brackets- 8005007
Bow & Stern Lines- 8004031
Heavy Duty Straps- 8005006
Shop around online and you can get some decent prices. I then took those prices to the local dealer and he almost matched them and beat them when you added shipping
I have carried my canoe on very rough trails and at 80 mph on the highway!
The picture below was on top of Ossipee Hill in Maine.
]
I have the same setup on mine (minus the fancy yakima rope...) the gunwale brackets do work really well and are compatible with any 1" round rack system. I recommend them to prevent side-side movement. Also, I get better mileage with a canoe. It actually IMPROVES the aerodynamics of the KJ at highway speed over unladden