Doubt on Service tax and other taxes

Dear All,

Please clarify,

The charges like service tax, stamp duty, brokerage must be a part of ECN or must it be a part of the monthly bill that is submitted to the customer. Ours is broking firm.

Also, let me know how is the stamp duty to be filled in ; is there any online system (efilling) in that.

Also, I need a confirmation letter from the client stating that he is ready to receive all ECN, estatements etc through his email.

Thanks in advance.