After getting advice from Thomas Amber (JISC Innovation Group) I realized that two "repository" serving applications are suggested: DSpace (http://www.dspace.org/) and EPrints ( http://www.eprints.org/software/). Also I realized that there are many implementation of those repository applications are available around the globe, including Jorum (partly uses DSpace) and the Nottingham University's EPrints implementation (http://eprints.nottingham.ac.uk/). Jorum may not be well used as a back-end for us and finally that both DSpace and Eprints are highly customizable. Also I found that although DSpace and Eprints are good at being repository, they are not designed to be a "social media" type of website
I and Suchith thought the best action to start the repository is to install and customized a DSpace instance. I did this on my localhost and at some stages this has to be transferred n a proper server. I found DSpace an expert product and capable of being the ELOGeo repository. The basic functionalities we expected are coded: User register, login, material upload, license agreement, permissions control, metadata control, search, RSS, etc. It will finally be hosted on the Manchester side of the project but at the moment it will be a good practice to install it here on a server at Nottingham University.