All the charter boats I have been on have been pretty well equipped, including paper charts, a chartplotter, mounted VHF, and at least one handheld VHF (and usually an auto-pilot as well). Part of the check-out on the boat includes operation of this equipment. So, I have never felt any need to bring my own charts, GPS, or anything else like that.
In addition, as mentioned, every company that I've dealt with provided a list of supplied equipment well ahead of time, so I could see for myself what was going to be available. At most, a couple of times, I have brought along my own cruising guide to the area I was going to be in.