Changing Text in 'Your Total' box (cant find it)

Hi,

I am trying to change the 'Standard Vat' text in the Your Total box on checkout_payment. I have tried the developers toolkit but cannot find where to change this. I know it shows up on checkout_payment page but when I access that file it says nothing like standard vat (hubby says its a variable from another file but we cannot find out which one).

The text I am trying to amend is the Standard Vat part in the image attached (just below delivery options text):

Any help would be appreciated - thanks.

ADDED: I have another issue also regarding the same box so if anyone can help with this also please - in the main website I have put the words (incl VAT) after each price on a product (we are changing from excl vat pricing to inclusive vat so really need to let customers know its now included). All looks great but at checkout in the your total box the following shows:

Is there any way to switch off the (incl VAT) from showing on every price at checkout? I really just need it on the main product listings but it looks silly showing VAT as being (incl VAT) etc.

Thanks again.

Does anyone have any idea on how to remove this 'Standard VAT' box from checkout please? It is really putting customers off and despite trying to locate it for the past few days I am still nowhere nearer to either removing that line from checkout completely (preferable as its shows the wrong vat when coupons are used) or to renaming it.

Any help appreciated.