Optimum grasski type & length:
For use with kite are important different properties than competitors look for. Speed is not so important but turning and durability is key. Not to mention most likely you will not kite with grasski on perfectly prepared slope but typically on some field with longer grass. Therefore you it is better to look for ski with length around 80 - 85 cm for ladies and 85 - 90 cm for men. And like was mentioned at begining, speed is not so important therefore using Endurance model is enough.