As far as assistantship is concerned check the websites of the unis yo wanna join. One of the strategy for the school hunt would be make a list of unis depending upon your academics and expereince. Choose some good unis, some medicore. Rank them and apply. Do not just apply in good schools because it is really very challenging to get into these schools. Atleast choose 10 unis to apply. But do not choose any unis that are not accredited cause its worthless. Hope this help. peace out