Need a well experienced - intelligent content writer with 100% fluent and accuracy in English

I need a highly experienced, intelligent content writer for my project with 100% fluency and accuracy in English. Specifically, I am looking for someone who can write factual content, so the writer should be able to conduct research and present facts/ descriptive information authoritatively. The content must still be constructed and delivered promptly. With a suitable writer, this content will be used for my present site's blog, so creativity and good grammar are essential!