I need to get my blog built with GatsbyJs

I have my Blog template built with React with all elements broke down into individual components. I need someone to take this template and build me a fully working static blog built with GatsbyJs. I feel it’s at max 20-25 Hrs if one knows how to use GatsbyJs to build a static blog with Markdown as the content, include pagination, generate pages for categories, authors, posts by categories, post by authors, include discus for page comments, include google analytics and integration with Ad services to display ads. Propose me amount to complete the whole project and not just by billing hourly. Request proposals only from those who has worked with GatsbyJs and React earlier.