Great question!
Surf and CerousMutor have some cards solely from NuWars films,
and there is a sub-set of Rebels TV Show (and the 3D Clone Wars Show) of VSET Cards,
they're simple-ish, with not too many new abilities not from the standard rulebook to learn.
They'd be great for something quick and easy,
in terms of making your own customs,
there were a few spreadsheet programs which made the costing algorithm
(folks had cracked the costing formula a while back),
so that helps cost your minis in the right ballpark,
to make simple versions of characters with abilities only from a given rulebook
(and, with a limit on the types of abilities etc) sounds like a great idea for exhibition match miniatures.
It'll be great to see what you can come up with
If you were thinking of having rarity correlate to complexity,
similar to the ideas that the "Legacy Format" folks were designing around,
ie
commons have 0-3 SAs etc,
uncommons have 0-5,
rares have 1-7
Very Rares have 2-8
that would have been awesome to see consistently used as a design principle from day one of the game;
it's as though in the WotC sets, no-one kept a design exegesis handy until the fifth set hehehe.
Clone Strike and Rebel Storm at 100 and 150, play as a very simple version of the game;
so, that style of design might help in making simple variants of pieces?
I've dabbled a little with low-res stat cards,
and they're what the locals have playtested over time, to arrive at different versions
when we play tested them,
we had just a paper format, which we tinkered with on the fly
(sometimes during a game, after a mini was defeated and brought back in via reserves)
and humorous sketches as placeholders for the actual sketches of some minis...