I am not sure that SolPartMenu can pull that off. It is a table-based menu that does not seem to lend itself well to anything outside of rendering rectangles (at least I couldn't get it to do more than that).

The HouseOfNuke HouseMenuSkinObject will probably be a better fit. The HouseMenuSkinObject can take an unordered list (ul tag) and create a non-table-based horizontal menu. It won't do what you want "out of the box" so you will need to be fairly proficient with CSS to customize it.

It can be downloaded here: http://www.houseofnuke.com (although right now it looks like the content on the site is offline). You can get the source code too.

For a tutorial on how to implement the HouseMenuSkinObject, you may want to check out the videos on DNNCreative: http://www.dnncreative.com/Tutorials/SkinningTutorials/HouseMenuTutorial/tabid/233/Default.aspx. (You will need to pay a subscription fee, but it's worth it in my opinion.)

To see the HouseMenuSkinObject in action, go here: http://skins.dnncreative.com/TheSkinDetails/tabid/64/Default.aspx. The example shows a vertical menu, but it can be implemented horizontally too.

I have had pretty good luck with the HouseMenuSkinObject. I had to tweak the source code so I could uniquely identify each menu item so I could display a different image for each menu item.

Start with that and let us know if you need more guidance.

Cheers!