The brands mentioned are widely available and pretty standard. Springbank and Highland Park are notable exceptions in superior quality, however. A couple other lighter, fruity sweeter drams might include Strathisla and Deanston, though they're not smoky at all. Another along the Springbank and Highland Park vein is Benromach 10.
For an ex-Jack drinker, you'll never go back to Bourbon (unless forced to do so at gunpoint) once you get into some of this single malts. That said, I still drink Bourbon - when there's no other choice.