Depends how you are going to get it to fit...off the shelf fitting kit or someone fabricating?

If you are going fabrication route I would look at some of the BMW diffs or Yank stuff as you can buy them in any ratio and you can get light weight alloy stuff that will take 700 bhp+ I have a Supra diff with weir kit but if doing it again I would go alloy as the Supra is a heavy bit of kit.