KDE configure button height

Hi,

In KDE (4.10, 12.2 64bit), can I customize the size of GUI elements like buttons? I wish the drop down list’s main button would have more height.
Below there is a screenshot of qt designer. The text of the labels overlap the button. It’s uneasy on the eyes.

View image: snapshot1

Edit1: This height is perferctly fine for the plastique theme. Problem is I don’t like it.
Edit2: It would be the best if these buttons would rescale them based on content (int this case text). Is that possible?