You have to take out the center detent ball between the shift rails. Then you can either use the single stock stick with an alternate shift pattern, or use twinsticks, to engage 2low.
Simply getting twin sticks (all they do is make it so you have an individual stick for each shift rail....one for high/low selection, the other for 2wd/4wd selection) will not allow you to access 2low....the center detent ball still has to be removed.