A local pro shop that does grips can either do the work or likely recommend a facility that can replace the shaft. you can then either ask for a recommendation or spend an insane number of hours researching the hundreds of options of shaft available. If you went to a website like Dallas Golf, you can scroll a long time through all the options. Depending on the shaft, the installed shaft would likely start at $100. Not counting exotic shafts that cost in excess of $500 just for the shaft.
A used 913 D2 would be about the same $100 unless you really love the 983K.