As far as I know, they're identical, apart from GTI skirts being textured and Ed30 being smooth (primered too I think).
But, the smooth skirts are riduculously expensive.
I'm in your position, and I've opted to have the GTI skirts flatted back by the bodyshop before they're sprayed.
It will cost more in labour but I'm damn sure not as much as Ed30 skirts would!