Get the E4 if you are dead set on owning one that uses Ar-15 mags, or a gen 4 if you want the more Styer look to them. Those will be the shooters, and can be had for cheap due to sales right now I think. If you want to get a collector one CDNN has some of the first gen still available I think.
Me I prefer the AUG
but each his own 
Khest
Me I prefer the AUG
but each his own Khest
