[SOLVED] two horizontal menus / bi-lingual menu

I have been asked to produce English and Greek navigation menus for a site and am wondering if anyone can suggest the best way of doing this?

I was hoping the theme may have the option to do this and that I could perhaps convert the category menu but this doesn't feel proper.

My thoughts were to have one English menu and then a Greek menu immediately below but my previous efforts can't guarantee the two sets of items to remain separate and they overspill.

On this site using the theme www.offmodern.com they have used two vertical menus at either side - how do you think this has been done?

All help is much appreciated!