New gearbox next week - but what oil?

My 2008 197 Cup is having a new gearbox fitted next week as the 4th gear synchro is crunching.

I've read a few posts about 'what's the best gearbox oil' and the consensus seems to be to stick with the original Renault stuff - but I can't find any info about what the original Renault stuff is. I assume it's Elf - but which one?
 
I use castrol syntrans, (75w-90) as its good for cold temp synchro alignment . Its really a personal choice thing. Have a search about on here as its been covered in some depth in other threads.