Sichuan peppercorns - best ones to buy and what dishes to use them in

Where would I buy the best sichuan peppercorns and what dishes could I make using them? Do they need to be ground or can you use them whole in a stir fry. I did purchase some from spicely organic and ground them. Can they be used whole in a stir fry dish? I noticed a lot of little twigs i mine and tried to remove what I could see. Looking for the best quality, best tasting. Would love to hear your ideas. Thank you.