I'm looking on eBay for a new fuel filter but I'm unsure which size to go for, my options are 6mm or 8mm, any ideas?

Daz.

go into motorfactors..... with whatever pipe sizes you need, and they will sort you out

mine is an oem bmw i think

It looks like it's already using 8mm so i'll stick with that
I'm also looking to get some 8mm clear fuel hose to replace the perished stuff, do i need to get reinforced stuff?

Daz.

fuel pipe research topic at the top of the engine and transmission page should help.