[TYPO3] Conditional seciot index?

[Pascal]

Hi, I am trying to set up a section menu which links to the different content 
elements on a page (for a newsletter page).
The 'Sectionindex' of the 'Menu/Sitemap' element does part of the job for me but 
I need a different presentation for de category links.

FE:
--------------
  [Menu/Sitemap]
  * category element 1
     * text element 2
     * text element 3
  * category element 2
     * text element 4

category element 1 [Header]

text element 2 [Text w/image]
some text here, possible an image

text element 3 [Text w/image]
some text here, possible an image

category element 2 [Header]

text element 4 [Text w/image]
some text here, possible an image

--------------

Would this be possible using the elements I have chosen or should I use a 
different approach?
If it can be done with the 'Section index', how can I configure my TypoScript to 
  markup de <li>-elements to use a different class for the 'Header' links?

Thanx in advance,
Pascal