My opinion, don't invest RESP in bank. To be frank, it's not a big amount of money, and don't need to spend too much effort on managing it. So, choose a large institution (like USC or CST) that are dedicated in RESP.
And, trust me, there are really little different among these biggest ones.
Pay attention to the terms on when/how you can quit, withdraw these money, and ask at least 3 agents before you buy.