Re: DROP C FOR 4 STRING BASS!!!
If you mean C standard, get a five string set, and discard the highest string. You’ll need to have the nut pulled and set aside, and a new nut made to accept the fat strings. Keep the original nut in a safe place, so you can easily go back to standard strings in the future.
If you mean D standard with a drop C, get the La Bella D-Tuna set. You’ll need nut slot widening, but not a replacement nut. At a C, the 4th string will have to be run high, as it’s only a .111”.
If you mean E standard with a drop C, get a five string set, and discard the E (4th) string. String it with the B, A, D, and G strings, and tune the B string to C. You’ll need to widen just the low string nut slot.