If you want easy, go Enjin. Personally I hate it and think it's too rigid, but it's the least work.
I've been using NamelessMC to run my site the past 6 months and it's good! Setup was a pain (you're going to need to know how to run a Linux server) but it's simple and flexible enough to build on top for assignment done. Some modules exist for the features your asking for already too.