After viewing your site... I'll get right to the point.
Beware of any bidder that is telling you that they can and will accomplish everything that you're asking for.
Judging by your post, you're in need of copywriting, SEO services, along with marketing & advertising.
FACT: Even the big Ad agencies have separate departments for those services. You would in turn be asking a "freelancer" to single-handedly take on a task of this magnitude. It's not impossible, but probably as challenging as beating Lebron in a game of one on one.
I've had the honor of knowing a few great copywriters, creatives and admen. However, most of them were only great, because they thrived in their given field. (ex. You'll be hard pressed to find a great copywriter that is a SEO specialist.) AND WHY WOULD YOU SETTLE FOR GOOD, WHEN YOU CAN RECEIVE GREATNESS?
As a professional copywriter, with more than 11 years of experience, I have successfully worked with clients & brands of all sizes. My personal recommendation would be for you to minimize your project specifications, and issue them separately. It is a copywriter's job to produce creative, effective and high conversion content that will lead your target audience towards a desired action (purchase your products and services, donate, etc). It is the SEO specialist' job to maximize that content, so that it is optimized for search engines.
If you would like to discuss how to best maximize professional copywriting services, please contact me