American English Article Writer for website

I am seeking for talented writer. You MUST have EXCELLENT English writing skills. Must have perfect grammer and spelling. I'm looking for 15 articles, and each article must contain at least 400 words. Content must be informative, interesting and concise. Not filler or fluff. Only unique, original content will be accepted. Each article must pass CopyScape. Must be written in American English, with perfect grammar and spelling. Each article must be proofread for spelling, errors, grammar and word count. We are looking for some talented and reliable writer on permanent basis. All articles written must be SEO friendly and have a keyword density of 3% The subject of article is rc helicopters etc. Must be able to do research on the internet, or have good knowledge of it. Please attach samples of your writing If you can do the following, there will be a lot of writing for you :) Also, prior knowledge of RC Toys will help.