Digital signage system (xibo)

We are looking to develop a DIGITAL SIGNAGE SYSTEM by Xibo digital signage which is an open source platform which needs to be used, for our project which would include a front end that contains several screens the allow customers to express their choices, to allow payments, upload images and delivers this messages into the system. There is the desire that this front end be visually appealing. There is also the need for a "moderating software" that examines any message for objectionable or in poor taste content, plus the ability of people to visually review any message for inappropriate content. The back end must be digital signage capable--able to send to screens in the field on a per screen basis. This must include a timing feature so that messages are held then released per a timetable or schedule. NOTE: Freelancer or agency with prior experience is a PLUS.