Motley fool is a bona fide - and very good - financial website. I subscrime to their newsletters, and as a result was able to get the cheapest loan in the country (at the time).
Regarding you going overdrawn though, do you have an agreed overdraft which you are going over, or do you not have a pre agreed limit. It's always worth having one as a buffer zone when incomings and outgoings cross. Either way, try your bank to see if you can get or extend the limit if, as you say, it is only a matter of pounds. If still no joy, try changing bank.