HELP-Time to apply and Bank statement stamped inside the UK

[alexkaido]

Hello there,
can someone please help me to clarify my doubt. I will finish my BA course in June, and intend to apply visa for my MA course starting in October.

1. When can I apply? - my visa expiries on 31st October, my course starts on 1st October, from the Tier4 Guide I can apply during the last 3 months of my permission to stay (July-October). I want to apply in PEO in early August, but when I called UKBA they told me that I can apply in PEO only 30 days before the start date of my course, which is September. Is this right, or I can apply in August?

2. Bank statement stamped? - I have accounts with HSBC and Natwest, both providing me statements at the branch with some additional letter confirming my balance, but refuse to stamp them. I have tried several branches, but same answer. I want to ask if I order statements by post, which are the original one, do I still need a stamp on it, or it applies only to bank statements printed out at the branch.

Sorry for long questions because of full explanation of my case. Thank you very much for your help in advance, I really appreciate it.