New pads or entire calipers?

I was replacing my wheel bearings today and noticed that the break pads were completly shot. The rotors seem fine, not scored. I am wondering if I should just replace the pads or the entire calipers.
I dont know how to tell if the calipers need replaced or if it is just pads? I can get the rebuilt calipers and pad assembly from car quest for 50 a piece, and I can get 4 pads from 4wd hardware for $15??? So it would save me some money. I have never done strictly the pads before, what is involved in this install, I have done the calipers so that is no problem.

Let me know
tony

are the calipers leaking? does the brakes pull hard to one side? if not just swap in new pads and spend the extra dollars on :beer:

Inner and outer pads wear evenly?
Pull to one side when braking?
Fluid leaks?
Rotors show signs of heat/ warpage (bad runout)?
If not then the calipers should be fine. Have rotors resurfaced if they're in spec. Do you use organic or semi metallic pads?Organics do wear out faster. :p