High torque low rpm BLDC Motor
Why would 150Kv 5ohm motor have more torque than 87kV 6.5ohm?


Well, the 87Kv motor has got more resistance, and, for a given supply voltage, the current must be less than the 5 ohm version and therefore, the torque would be naturally less. Torque is proportional to current taken. More torque means more current taken. Measure the current and then compare torques.


  Where can I buy such motor?


That's an off-topic question but I wish you luck on your quest.