XRAY - Model racing cars

Hello,
i'm planning to build mine Tq kit, but i was wondering wich diff oil setup i have to use in the following conditions.

We like te race pinions, and to jump of the high sanddunes.
It is loose sand,an quit a little bumpy.

This buggy wil be used to bash most of the times in this area.

I will use CPS value, instead of the Xray value.

Annyone an idea of wich setup/setup sheet i have to use??

I have used the search, but since i'm new here, i diddent come up with the apropriete results.

Here are some pics,of the area.