First of all i have to inform you that if you dont have written permision from the bank about the website you will put yourself in great troubles!!!

It is easy to write the scripts by using php , and then wirte the appropriate sql commands at mysql. There is lot of great books that they can easily help you do that.You can also check at the official web pages of php and mysql to find lot of instruction,documentation and examples.

Now if you want the scripts ready, i dont think that it is possible to find them but you can check at, or just through a search engine.
Allow me to tell you that the online banking scripts must correspond to your needs, it will be difficult to find the appropriate scripts by chcking in the internet.Have also in mind that is the script are not totally correct your webpage can easily fall on attackes like sql injection and many more.
I hope that i help.
Take care