Personally, I would put LSE and King's as my top choice (I know people who did both those subjects at those unis who are now working in investment banks), and UCL as my back-up.
I think Information Management is less relevant to banking, but may be quite strongly related to consulting firms especially Accenture etc.
To be honest, firms don't really care what degree you have. I have friends in those industries who did degrees in Chemistry, History, English, Geography etc. - all that matters is a good grade from a good uni. The relevance of the subject may help you answer questions in the interview/assessment centre, but that's it really.
As for the personal statement, I wouldn't worry about picking subjects to make your personal statement easier. I applied for totally different subjects, and that was clear from reading my personal statement, but I still got offers from all the unis I applied to (LSE, King's, UCL, Oxford). The personal statement is more about selling yourself, than proving you know what subject you're applying to - that's a given.