It depends where your priorities are. If your trainee lacks driving and/or handling too, or you want it to go up anyways, training "one vs one" is definitely a very good option. Since both, "jump shot" and "one vs one", are 2-position-training you can easily switch depending want you want to grow faster.
In my experience training JR doesn't have too much of an impact on JS and it is one-position-training, so maybe you wait with it till the other skills are as high as you want.