Ok, man. I am a Seotoaster user like you, so I can share what I did for myself. Can you re-explain me what do you need exactly?
With the default SeoToaster main menu you can get a single submenu level: 1 row of parent items, each parent with submenu items (no sub-submenus to be clear.)
If this is enought for you, I can share my CSS-only solution - yes, no JS required :).
If you want a more complex layout, you will need to edit the core files of the CMS. I did also that and I can tell you how, but you must be confortable with doing it.
Let me know!