Article rewriter for article spinning (long term)

I need an experienced articles rewriter to rewrite articles on various topics on a regular basis.I need articles done every few days. Articles are about 300-400 words. I will provide the articles -Each sentence must be spun 5 times -Article must be at least 30 % unique. -Article should be provided in proper format so that it can be pasted directly in article spinning softwares. - You must understand keyword density and SEO. Articles must be optimized for the given keyword phrase with a minimum of 2% keyword density but preferably 3% to 5% - Articles will be reviewed by us , if article is not approved by us you have to rewrite the article. - You should be able provide samples of work. - You should be able to meet deadlines. Thanks