Hi

Although it's a manual, an ATF is the best fluid for the gearbox and the best options are the Amsoil ATF, Red Line D4 or Fuchs ATF6000, although the others are fine as cheaper alternatives.

http://www.opieoils.co.uk/c-771-dexron-iii.aspx

Any of these in a 75w-90, 80w-90 or SAE90 are fine for the diff, although the 75w-90s are the best options.

http://www.opieoils.co.uk/c-970-limited-slip-diff.aspx

Cheers

Tim