Create interactive mapping website/pluggin

I would like to set up some mapping software, such as google MyMaps or popular Hotel booking websites than enables people to find drug and alcohol treatment facilities easily. We have a project on drug treatment operating in 15 countries, and would like to start with facilities in these countries, but will ultimately like to be open to treatment facilities all over the world, in a crowd sourcing model. We would like the each facility to be linked to one or more photos, a web site, and some information about the facility. Even better would be if the facilities could be searched, i.e. by type of facility, and if some data on the facilities (such as the number of patient treated in each facility) could be mapped graphically. It would also be good if people could post comments on each treatment facility, like trip advisor. The map would be open to the public, and would either be embedded in our website and hopefully other people's websites also, or could also be a standalone website. While I would like other people to add to it, like wikipedia for example, there would need to be some mechanism of monitoring new additions in case they were inappropriate. Please include an estimate of how much time you think this project would take, and how many hours work.