Marathon des Sables gear

I am beginning the complicated process of trying to work out what gear to take to the Sahara desert with me. It is tricky for two reasons:
1. I have no idea what gear I need whilst running around in the sand.
2. I am very aware that if I make any bad decisions then there will be nothing I can do about it when I am out 'there', and I will simply have to get on with it.
Thankfully there are people who have gone before us and who have

written it all down

. A big help!