I don't know if your cruise include Stockholm, but if you do, don't take any Swedish currency. Even small places accept cards and there are more and more places that will not accept cash at all . As I know Denmark is going the same way. Living in Stockholm I have stopped carrying any currency at all when I leave home, only carry my plastic cads. I only know of two places where I need to take cash and they are not places where visitors to Stockholm are likely to go.
If you have several days in Stockholm Sigtuna could be a nice tour one of the days. But if you are here for one day only you should definitely stay in Stockholm. There are many things to see that are more interesting than Sigtuna, and Stockholm is a beatiful city.