Yes! You can pledge for as many as you like. Just adjust your pledge upward to account for the additional sets. For instance, if you would like to get two of the $44 pledge levels, just back the campaign at the $44 pledge level. Then, adjust your pledge to $88.
If you need to do this after your pledge has already been made, just click the "Manage Your Pledge" button on the Kickstater page. Then click "Change Your Pledge" and Kickstarter will let you made the adjustment.