Organic groups..?

Hello.. I'm working on my little app here.. have figured out login, upload avatar.. and so on.. http://metroklub.sk/drulog/bin-release/DrupalLoginApp.html <-- don't know how long it will hang there.. anyway I would like my users to create their own group and let others to join in if they are approved.. nothing really complicated [i guess] but now I don't know which direction to take.. should I role out my own piece of php code with included bootstrap.. or install an organic groups module and try to make a service for it?.. [I don't think I'm skilled enough to write my own services].. or just save nodes and somehow work it out with permissions..? well I'm lost and would like to hear some other opinions..