HI i want to buy a SM50cc and i want the best i can find after a big research ihave choose the DERBI DRD PRO 50CC AND THE DERBI SENDA X-TREME 50CC.I want to ask wich of them is FASTER with the most max. speed and more HP ,wich can tuned beter and have the beter driving skills.I wait for anser (^_^)