I'd recommend the Club Step.
The Super Step is pretty, but I don't think it's as height-adjustable (it's good as a weight bench, but not for stepping). There are only 2(?) different heights, I think, in 5" increments, while the Club Step is infinitely adjustable in 2" increments.
I've had my Club Step for over 12 years, and I consider it one of the best fitness purchases I've ever made.
You can buy it in either the black/grey combo or a teal/purple combo.