rutierut:
Voltage Range: 20-48v
Non Load Current: 2.0A
Maximum Power: 6500W
6500W is about 8HP and would send that board at absurdly fast speeds. A well-trained athlete, for a short duration, is capable of about 250W of power. If you're running at the recommended 20V minimum you shouldn't need more than a 30A ESC.
The practicality of loading enough batteries onto the board to provide that motor with enough power to meet its needs is also a consideration. Even at 30A you're going to need a crapload of batteries.