Anyone who sells Valeo clutches should be able to order the part you need... but unless your clutch is immaculate, consider changing the whole kit.
If your chassis number is greater than 0061512, then you need either:
Valeo 3-piece kit: 834005
Valeo 4-piece kit (includes a DMF): 837005
The release bearing alone (only worth it if the rest of the clutch is brand new): 804521
If your chassis number is 0061512 or lower , then you need either:
Valeo 3-piece kit: 834036
Valeo 4-piece kit (includes a DMF): 837004
The release bearing alone (only worth it if the rest of the clutch is brand new): 804524
If you want to try online, type in "Valeo NNNNNN" into eBay etc. and you'll get Valeo, Luk and other brands that are compatible.
Ralf S.