Sensor leads
 

Apart from length, are all sensor leads the same? Will all leads fit all brushless motors and all ESC's? Are some better quality than others?

The plug type and pin-outs are standard across all makes. I think it's in the EB rules somewhere that they have to be, so you just need to make sure you select a suitable length.

Hope that helps

Motor end is always the same, ESC end is the same in 95% of cases. GM has a different connection at the ESC.