Will the embassy accept savings account statements for Non O-A visa applications?

Hi, I have a couple of questions about the finance aspect of the Non O-A visa. Last time we applied (in the UK) we had money in a current account, so we printed off three months worth of statements and had the bank sign and stamp them. This was fine and the embassy were happy with it. We are going back to the UK soon and will be applying for another Non O-A visa, but our money is in now a high interest savings account, and the pensions we get are just short of the monthly requirement for the visa. My questions are - will the embassy accept statements of a savings account if they are signed and stamped as before or does it have to be a current account? Or we could do a combination of pension income and the money we have in a joint current account, but the embassy will need an income certificate - what is that? Many thanks in advance.