I can't be very helpful about perch... I think most of the Hwy 60 lakes have them, but I don't know if any have eating sized perch. A lot of Algonquin lakes just have tiny ones.
But I'll give up a convenient spot for rock bass, since they're invasive and not very popular. Downstream end of the 195 m portage on the Madawaska River, right around where the Track & Tower Trail from Mew Lake Camgpround merges with the Old Railway Bike Trail. Toss worms into the eddies. Have fun.