Build a Website / simple online forum

Looking to design a website that is hosted either on my servers or in the cloud. The website is basically a message board where users have to enter a password to entire the site. Once the password is entered, they get a list of 30-40 names. If they hover over their names, they get a picture and some info on that persn. Once they click a user, they can send a short message that goes via a text gateway either SMS or email. The second part of the site is a forum where people can post short messages. This will be displayed to all other users that log on to the site. The messages can be flagged with three priority levels, 1, 2 or 3. Every day at at a specified time, this will disappear and will start from scratch. this is the basic format. This will be an on-going project and may be scaled upwards in the future. The current budget is to get a working prototype that I can host myself. Please provide your experience with this type of infrastructure as well as the languages you will use to create the site. The site MUST be accessed from a mobile device (android and ios) and should scale down to a mobile-friendly view.