The Tone Rider bass pickups typically use white/yellow for hot and black for ground (same for their other single coils). You don't need to strip all the black wire to bare, it makes no difference insulated or not, just solder the bare 'tip' to the indicated ground point (ie. back of the pot).
More expensive pots are usually closer to their specified value (250K vs 300K or 200K etc.), less prone to 'scratchiness' and tend to last longer. You can always start with the supplied pots and upgrade later if you feel the need.