I do love the idea of the cyclical nature of the force, because it suggests there was a deeper meaning that both the Jedi and the Sith have always missed due to their blind hatred of one another.

However, if you want to use the original ideas that were revealed of the last trilogy I think you will struggle because RotJ ended the story that Episodes 4 and 5 built up. Therefore, you can develop a whole new story with some of the characters or new characters or whatever. Or I think if you want to extended it in the way that was first suggested I think you would need to rewrite RotJ first because things like Leia being Luke's sister and the Emperor being killed make it hard to carry on in this way. Purely because you would be restricted by what has gone on in the films, and restricted by the rumours which would guide your new stories, and then have to make your stories fit within those lines.

If you want to just expand after RotJ with new stories then based on what you have said I would read the Heir to the Empire books (if you haven't already) and note down every little thing you like about those stories. Then figure out which ones don't contradict what the PT showed us, and then build your story around that. Otherwise you are trying to redo exactly what Zahn did but possibly using some of his characters and ideas so you have to ask yourself can you do it better than he did? By all means try, but those books would provide some food for thought if this is the direction you would like your stories to take.