My advice is to purchase a true and tested winnower, you will save money vs testing and trial and error.
I just visited Cacao Cucina in Tampa, great winnower for 11,000 USD so for 8000 Euro, you have never to worry about it...
But on the other hand, I visited a farm in Hawaii winnowing with a small vibrating table, and a modified Shop Vacuum from the hardware store.
Nice thing about buying from Cacao Cucina is the machine breaks, winnows, and results are very good, very low shell content.