Question: What eras are you planning, or are you using any particular era at all? Star Wars has a serious blobbing problem where almost every era is defined by two or three mega-blobs (traditionally the good guys, the bad guys, and the Hutts, with sometimes the Mandalorians also - that's barely enough major factions for a Mount and Blade mod and like a third as many as you want for CK2) and a dozen or so tiny one-system or often enough even one-planet third parties. The only exception I can think of is the immediate aftermath of RotJ in the old EU, when the Empire balkanized.
Another question: If you're going to have multiple eras, will they be within a reasonable timeframe of one another? Canonically, only the 150 years or so from the Clone Wars to the end of the old EU happened on anything approaching a workable scale, while the distance between TOR and the PT is long enough to fit a complete CK-HoI playthrough within, without one single major event on the timeline to use as a bookmark in between.
Personally I would recommend serious canon-overhauling to limit the power of the major blobs in eras like the Old Sith Wars, Great Galactic War, and Clone Wars, boosting the influence of third parties, and compressing the timeline down to somewhere in the range of CK2's seven centuries.