Article writing, re-writing work

I need a native english speaker (or someone with a native ability in english) to write or re-write good articles for me. Job is for 10 articles, of which a half will be re-write jobs. Articles is based on semi-technical products, so knowledge in electronics is an advantage. Articles must be of good quality (no spelling mistakes, good grammar, readable, etc.), original (we will be checking), approx 600 words (no less than 550 words). You should have previous work as samples before we proceed. The copyright for the articles you write are transfered to us. You are not permitted to re-submit, re-use or distribute them in any way. Ongoing work if the quality is good.