I hiked the Silhouette Trail in 2011. It's about as good as hiking gets in Ontario, and I recommend it to anyone who loves beauty.
My advice for an overnight would be to follow the good advice already given. Go counterclockwise, enter the trail from the highway, not from George Lake, ( this will save a lot of level hiking on old forest roads) hike up to the unfortunately named "The Crack" and then continue northeast toward Little Superior Lake and Proulx Lake.
The view from the Crack, and The Crack itself are simply awesome, and a real highlight of the hike. And the beautiful blue lakes along the trail, surrounded with quartzite rock, are a treat.
I travelled clockwise so I came down the Crack, but I could look at my maps and figure out approximate travel times ( for a 47 year-old male in okay shape, not out to set any speed records, but trying to stay safe and injury free when hiking solo).
PM me and I'll take a look. In a day you could climb the crack and get to some of those awesome lakes, certainly to Little Superior or Proulx, and depending how keen you are, to Heaven or even Bunnyrabbit. But it's diminishing returns, as the first two lakes give you that lake experience, and you will want to dawdle on top of the Crack and take pictures. And Bunnyrabbit, which would be an awesome lake anywhere else, is merely ordinary after seeing Little Superior and Proulx.