Same bat length, but weight might change
In my opinion switch hitting isn't as important in softball as it is in baseball because of the way the pitch is delivered. In baseball, the overhand throw comes from a 3/4 position, so the pitch is thrown in a way that looks like it will come right at a hitter who is hitting from the same side as the pitcher throws (i.e. righty pitcher, righty hitter). Being able to move to the other side of the plate gives you a better look at the ball.
In softball, the plane of the throw is vertical, so it's right next to the body on either side. There's nothing to make it look like it's being thrown at you, and your view is pretty good regardless of which arm the pitcher uses to throw it.