Rear carriers 282mm to 310mm upgrade

[Zac]

Hi all,

I own a 2007 SEL Estate. It currently has the 282mm rear discs. My question is, what's required to upgrade from 282mm to 310mm? The carriers look like they will take the bigger disc, as there's quite a lot of space left.
Reason I'm asking is that I recently changed the rear calipers/EPB and I now have the bigger 41mm piston calipers (they were given to me erroneously), but they fit/work all the same. So do I just need larger discs? I already have 17 inch Monte alloys, so alloy size isn't an issue.

Thanks