I would suggest you to go for F7 & F8. Because F7 covers Accounting standards & F8 need accounting standard knowledge too
Not the best, but not the worst either.
For me, the best combination was F5/F9 and F7/F8 as these complemented each other most (in my opinion, as had lots of overlap).
The overlap you will see will be about Cost of Capital, Tax, and Ratio Analysis. Whilst Cost of Capital features extensively in F9, it is shown in very basic terms in F7. There's limited knowledge of Tax required in F7 and F9, however Ratios features heavily in both, and you will most probably have a 15 mark question in F7, and possibly F9. However, Ratio analysis also features in F5, which, coupled with other topics, makes it more suited for F9 than F7.
The other advantage of F5/F9 combo is that there's a 4 day gap between exams (Mon to Fri) rather than a 2 day gap with F7/F9 (Wed to Fri).