Looking for free webgis & online database solutions

I am currently building (under wordpress) a website that will deal with a fungal taxonomic group (i.e. lichens).

One of the aims of the website is to propose a solution for specialists around the world to make their personnal online database (can be resumed by : one species, one observator, one date, one location (wgs84 coordinates), comments, etc.).

You can for example see GBIF to see what I'm looking for (+ the personnal online database, that is missing on GBIF) : http://ift.tt/2idxjhB

The perfect scheme would be for example :

1) they register on the website

2) they have access to a form to save datas (e.g. like an excel sheet), (the species name can only be selected in a list (and the list size depend on the "level" of the specialist).

3) they choose if the data are private or public. If they are private they can manage them, edit maps, store them, etc. If they are public (its good!), everyone will be able to see it when requesting for informations on a particular species...

4) It's possible to display maps of presence, of one, or a list of species, etc.

Do anyone has ideas to help me in this project ? I know well how to use QGIS, but I'm not familiar with webgis & database, etc...

Many thanks for your help !