is there any way i can put 2 or 3 transfer cases in my 99 chevy 2500 4x4  

The easiest way to you use a reduction unit off of a NP203 on a NP205 or Dana 300 with a adaptor for a 3 speeed Tcase but honestly if you take time to gear axles properly you will have little need for it 99% of the time. Most that seek deeper tcase ratio combos procrastinate on using proper axle ratios.  

on that same truck do they make a bigger lift kit than a 6inch