I just found an interesting site providing useful guide for comparing the different bank accounts and overdrafts to choose from, check this out: Banking Guides
It really is worth exploring the limits on any account. Something that many banks are doing now - and almost a scam - is to offer high interest rates on savings.
The small print being it only applied to the first couple of grand, and you need to put in a large lump sum every month. And the interest rate after is pants.