What resources should I take advantage of when searching for an HTML builder for my landing pages?

Who can you recommend to build a HTML 5 landing page website for A startup that aims to attract a technical cofounder/investment? The startup is about finding information that is not on the internet. The website design brief is ready to go! I know I can look on websites such a Upwork, Fiverr etc but I believe a better chance of finding someone experienced that I can develop a long term business relationship…