Web based user generated content platform

I’m seeking help in putting together a quick prototype for a web based, user generated platform using an existing open source script (http://www.question2answer.org/). If this script is not suitable, I'm also open for you to suggest any other platform and customize it to get the required product. So really looking for something very quick done here.

I have the mock-ups ready (please see attached- don't get confused I'm looking to get the web based platform done, NOT a mobile app) so they'll come in handy.

Please get in touch if you’ve relevant experience (with examples of previous work). Also send me an estimate of how long it'll take and a ballpark quote. Happy to discuss and share some more details so please let me know. We're a start-up and not a big company so it'd be helpful if you are flexible and have worked with start-ups before.

Kind regards
Shahrukh