The 18650 25r is great battery for high current drain , however capacity is not its strong point,
Are you building 14s6p, 51.8v 15ah pack which will take most of those cells, a couple left over in case you have a bad one, it'll be able to put out 120a max so will easily power your 1000w motor, you have just got to find a BMS to suit your controller and batteries requirements e.g. A 50a bms will be good as it won't be working the cells hard, let's hope the quality is there as you haven't named the cells.
I think I've got most of that right but correct me if I'm wrong guys.