A lot of costumers buy the raw silk from Dharma Trading Co. I'm not if they ship to France or not, you would have to check. It is the best price I have found for this type of fabric. I use it in all my commissions.
Here is the material: http://www.dharmatrading.com/fabric/silk/black-raw-silk-35mm-45-inch.html?lnav=fabric_silk.html
Worbla and Wonderflex are made in Germany, so you should be able to find a supplier in Europe.
As for a lightsaber, you do not need one for approval into the 501st as it is an optional accessory. But we all love to have a good lightsaber in our hand! I personally have used Ultra Sabers in the past and have had great experience with them. I just ordered their most basic silver hilt with a red blade, nothing fancy, simple is better for the KOTOR era. If you want to have an accurate Nihilus hilt, I got mine from Moonbase Creations.
Moonbase Creations: https://www.facebook.com/MoonbaseCreations/?fref=ts
For the pattern, most of us use the Simplicity 5840 which you can order directly from their website.
Pattern: http://www.simplicity.com/misses-men-teen-costumes/5840.html#sz=30&start=82
Hope this helps!
Cheers,
Nef