I use only stock cables.
On the throttle, the key is to eliminate the throttle play so you are sure to take full advantage of the power at full throttle. To adjust, losen the adjuster nut (with motor off) at the throttle housing, and gently feel the play as you turn the throttle off idle. Adjust the cable so there is not any initial play, and then retighten the nut.
I check throttle play before every race, but this doesn't require adjustment very often.
Rick