You can contact Steve at Canaan.
steve@canaan.ioI'm pretty sure you can also just submit an order that size but it doesn't hurt to touch base first.
They also sent out an email yesterday about a price drop I think the 841 with June delivery is down to 958.
Wow. It's like the price drops to keep pace with the diff increases... Crazy to think they used to be 4x as much!