Krm240
If you have electronic controls I think will be much easy to add another shifter on the console. However if they are manual morse type controls then you will need 4 new extreme cables. 2 x 15 footers go inside helm to the console and then from the console one 15 footer to the throttle control on the engine and then a 20 footer to the shift linkage. Those were my measurements for a 26 footer so make sure you measure your own.
What year, model, Sea Sport and engine do you have?
Dave