Some names listed on the site with *sun* in them: Assunçäo, Assunta, Asun, Asunción, Aysun, Josune, Sunday, Sunita, Sunitha, Suniti, Sunngifu, Sunnifa, Sunniva, Sunshine.
I can also think of Sundown and Sunrise, though those sound slightly 'hippyish'.
I'm not a huge fan of the name Sunniva, but I wouldn't mind seeing it on someone else's child.