Form 1116 and/or 2555?

I'm working on my 2009 taxes and I'm a bit unsure about the FEIE vs the Foreign Tax Credit.

I've seen someone write on another post that the 2555 and the 1116 must be filed in addition to the 1040 and in another I've seen that just the 2555 is filed so I'm not sure if I have to do both or what the purpose of the 1116 is for is the 2555 is being filed.

Another question I have which I haven't been able to find a clear answer to is regarding proof of income.  Must I provide a form showing proof of income or is the 2555 enough?  All I've got is a payslip which goes up to Dec 31.

Thanks in advance for your help!

If your only income is earnings that qualify for and are entirely excluded by the section 911 exclusion then there is no point in filing an 1116.

If you have other foreign income such as UK bank interest, employer contributions to a UK pension plan or child benefit then you may want to file an 1116.

There is no need to provide proof unless audited.  A UK payslip may not have UK employer provided life insurance or pension contributions recorded and might likely the confuse the IRS.