QUOTE(Boo Radley @ Jan 6 2007, 11:08 PM)

I think FRSM would be the best to take!

Apart from all of those pesky pre-requisites

Choddy, don't be in a rush to do a diploma. Grade 8 distinction is fantastic, but if you look around the diplomas board you'll see it's littered with people who've underestimated the leap between Grade 8 and DipABRSM. That said, if you and your teacher think you're capable of passing, go for it - and as mrbouffant said, the best diploma for you is the one you can pass!
Have you considered the Trinity Guildhall Performers' Certificate as a stepping stone between Grade 8 and a diploma?
If you're ready and raring to go for those post-nominals, have a look at the different syllabi, not only to identify the exam which you can pass, but the one where you feel you'll enjoy the journey too. If you don't want the hassle of preparing for supporting tests, then consider ATCL; if you want the challenge of quick study, programme notes and viva, then look at the DipABRSM.
Let us know what you decide