This little "How To" explains how you can add images to the top and bottom of your categories. Using this method will also place the categories title in your new table. If you don't want this, just remove that postion of the code.
In order to have the spacing, you need to use Zacharys forum space mod.
That can be found here: http://www.vbulletin.org/forum/showthread.php?t=88983&highlight=Category+Spacing
Install that First!
After that modification is installed, we need to create 2 custom class definitions:
ACP > Styles and Templates > Style Manager > Hit "GO"
Scroll down to the bottom where it says "Additional CSS Definitions". Edit the following code to meet your needs then add it and save it.