SEO for a Website in SPANISH - 1 Keyword - 1URL

I need someone with a good knowledge for SEO and with experience in linkbuilding and SEO. I only want WHITE HAT Techniques! No black or gray hat ones! The website URL is in spanish and so is the keyword(s) I want to promote, so the articles/links and other promotion should be done in spanish. This is the reason I need a spanish NATIVE to do the job. This is a 1 URL - 1 Keyword Job! No more than 50$ bids, thanks.