I started with free pastry..I've had a great experience with it. It was very simple to set up and run a ring of nodes. I've been mainly using PAST (File storage) and its been quite easy to get running. I'd suggest having a look at the PAST tutorial here. https://trac.freepastry.org/wiki/tut_past
The code is over simplified in my opinion but you say that is all you need so I guess thats ok.