Depending on how you level it will depend on your shock situation. If you use new steering knuckles you will not need new shocks. If you use hockey pucks on top of the springs you will likely need longer shocks as they will be extended that extra 2.5". Either way you will need an alignment afterward.
Just a suggestion, 2" typically raises the front of an 02-05 to level on all 4 corners. I have only heard of people having problems with premature ball joint wear outs on the 2.5" and above hockey puck levels.
Agree. Alignment is a must anytime you do suspension work. As far as shocks go, I would replace them anytime you raise or lower a vehicle more than an inch. They don't come with a ton of travel to begin with, so shortening or increasing their travel will affect their performance and ride quality.