I wouldn't fear a used WRX too much. Look for an unmodded one if you have worries. Run away from anything that has or has had a manual boost controller on it (look for new vacuum lines leading into or away from the turbo).
In Ohio, the Evo and WRX were about 50/50 on the street. Since I've moved, I have only seen one Evo in Fairbanks, but there is literally a WRX on every corner.