@Wisper And if you do use the ready-made truffle shells (I highly recommend this too), then also buy the matching truffle shell filling/sealing tray. Makes it much easier when piping the filling and capping them off.
I bought the thick plastic one from PastryChef.com (I think it was around the $90 mark), but they don't seem to stock them any more. The only US online place that seems to have trays in stock at the moment is AUI (https://secure.auifinefoods.com/metal-sealing-tray-for-truffles-0041500000) but their thick aluminum/steel version is expensive ($235) for a metal sheet with some shaped holes in it — but it will last forever. If you're in the UK, then Home Chocolate Factory has them for £73.