Onpage content creator

I am building a site that will be translated to german.

For that I need to have the english version of it ready.

I have the content ready, I have the website design ready with demo content.

What I need :

1- Someone who can research and understand the niche I am into.

2- Someone who can read the existing articles and place them inside the columns in the website.

3- Make it seo friendly so that google ranks the website.