So I am assuming that to do a shackle lift I buy one set for the back and one set for the front?  so two shackles for each?  (4) shackles and (4) extended shocks.  Is this everything I need for a 2" lift?

As the owner of a shackle lift you are going to have to buy some outrageously long shackles for 2 inches of lift. I bought the biggest ones that Rocky Road Sells and it gave me just enough to stuff some 235/75/15's under my sammy. and it only gave about an inch of lift also you are going to have to correct the steering angle.  never really bought different shocks wasn't really enough lift to warrant it.

Just my opinion, not sure what you are going to be using the rig for, but I would pick up this kit if you are looking to lift your samurai.
From Sky Manufacturing, www.sky-manufacturing.com.
 Sky's Stage 2 Samurai Spring Over Conversion

Price - $380.00

you will need to buy lower front shock tabs buy  lower rear tabs if you want to gain longer shocks in the rear

here is what my zuki looked like after the shackle lift with 235's

here is what it looked like after the sky's lift with some 32's

Just my opinion but for a budget lift the sky's is an awsome deal. don't forget you will need to buy lower front shock tabs

start the how to best lift your samurai war NOW.
Bash

As your only moving one end of the spring you need to extend the shackle by twice the lift, ie 4" longer for 2" of lift. The other problem is that the axle will tilt and the steering geometry will change fo the worse. Some people don't seem to mind but others really don't like it. If you do the shackle lift then make sure all the bearings and steering components are in good shape and that your steering damper works too.