Web site development - Budgetary Plan

We are contemplating to start a web site on the lines of Linked in dot com, but for a specific industry . The site will involve employments,posts,messenger ,semi developed pages of stakeholders with videos and images,classified ads among other facilities. First year membership would be around 1000 with max at 50,000 in the following years. Development work will be continuous and may span over a year and half. We are penning down the budgetary plan to enable us to finalize the investments and fund requirement and take the next step forward. Domain name has already been registered. What we need, is a complete plan for development of the website and maintenance of server. Detail of front-end and back-end platform should be mentioned. Also, advice any technical shortcoming which may need to be taken into consideration on the onset. We prefer developer from India, but do not have any problem working with person/s from other countries. Please note freelancer with required knowledge and capability should involve themselves. This is not a pageview website. We would seek examples of work done by you in the past. Please note that bids here would be irrelevant.