Ceramic mini capacitors
Ceramic capacitors are excellent for saving space in a guitar cavity due to their small size. At such small voltages, as is seen in guitar electronics, the type of capacitor makes little to no difference as the capacitors are not being pushed to their limits. This budget option will give you the same (or negligibly different) results for a lower price.
0.022uf capacitors are most commonly used for humbucker and P90 loaded guitars. 0.047uf capacitors are most commonly used for single coil loaded guitars. You can achieve more treble roll off on your tone control with a 0.047uf capacitor and vice versa - choose to taste!