My shore fishing in the Western GTA hasn't brought me much success this year so I'm planning on renting a boat at Island Lake (Orangeville) or Little Lake (Barrie). Other Lakes within an hour of Mississauga where I can rent a boat are also viable but I believe these two are the best. Which one would you recommend? I'm looking for bass and/or pike and size isn't as important as quantity for me as long as the bass are greater ~1 foot and the pike are greater than 1 and a half feet.
Both are good options. Island Lake can be more difficult to fish this time of year due to thick weeds, but fishing weed edges will be productive. If you fish effectively at Island Lake, there is a good number of pike between 18"-24" to be had. But if you don't know how to fish through heavy vegetation, you may not catch anything.
Little Lake has been producing and a friend of my fished there recently and reported decent catches of Bass and Pike. There are certain areas of the lake that is more productive, but since I've not fished the lake personally, I can't really comment on which spots to fish.
As I've always said, it's more about how you fish than where you fish. If you are new to fishing from boats, the sudden increase in mobility and availability of locations can be intimidating. Everywhere simply looked good to fish and it can be difficult narrowing down prime areas to fish. Structures tend to be on a bigger scale compared to shore fishing. Often, there is so much water to explore that it could be hard to fish all the areas thoroughly given limited time.