Advise New US-based Startup

US-based startup in early planning stages. This is not a coding project. We are looking for advice on what the site should be written in and an rough design timeline for initial site roll out. Our goal is not to build a site that has to be redesigned if traffic starts to build. Our goal is to develop a platform that can expand as we add VMs. We are looking for a consultant that has worked on new platforms and grew to a mature web platform. Our platform idea based on a construction and bidding.