Here is how I look at this question.
First and foremost, so you and everyone knows upfront, I HATE body lifts.
Here are some pros and cons of each.
Body Lift
Pros:
Inexpensive
Allows for running larger tires
Can be easy to install (1" body lifts)
Limited to 3" (I think even that is too much).
Cons:
Can be difficult to install (radiator relocation, shifter extension, etc).
Expose the frame and shows gaps in the engine and rear storage compartments through the wheel wells (looks like ass IMO).
Limited to 3" (I know some people would like more lift).
Still running the factory suspension.
Suspension Lift
Pros:
Allows clearance for larger tires.
Usually increases flex.
Doesn't look like ass.
4"-6" lifts are available from many companies.
Replaces factory suspension.
Cons:
More expensive.
More difficult to install.
Supplied coil springs sag (so get a lifetime alignment!!).
No matter what you do, make sure you consider re-gearing the differentials when you get the lift. Find out what size lift you want, what size tires you can clear, what gears you have now, and then you can determine what gears you will want.
If you have any questions, please do not hesitate to ask.