There is a lot of truck traffic at both Detroit and Port Huron. If you are not too long you could save some time by crossing on the ferry at Algonac or Marine City to Ontario. The ferrys do accomodate some semis. Algonac has a great state park on the river to watch the lake freighters. If you are in the Detroit area you should stop in Dearborn for the Henry Ford Museum and Greenfield Village. Henry Ford opened this in 1929 and it is "where history comes to life".
Definitely avoid the 407 ETR. If you are over a certain weight or size you are required to have a transponder. If you don't have one they can stop you and give you a $250 fine every time a different officer spots you. You won't need to use the 401 for very long either because you will be going up the 400 to the North Bay area. For a slow trip you could just follow the road that follows the Lake Hruon shoreline. very slow but a lot of small interesting towns.