I would say you could go ether way. You could all ways save all the parts and put it back to stock if you go the 4 speed route but then again there is nothing wrong with a 3 speed. In the end as long as you are have fun it all good.
Remember a TKO 5 speed has pretty much the same gearing as a 4 speed except for 1st and of course 5th,I don't remember what first gear is but you better be shifting real quick and if it's a long distance between lights with a 4 speed the motor will max out and the 5 speed will just keep on going by.Everyone has their own choice the 5 speed just happens to be mine for all around fun