You won't find differences from manufacturer to manufacturer with mainly street driven clutches as it pertains to one brand being vastly better than the other. Just because you're getting an ACT clutch, might not mean you are getting the right one.
What you'll need to pay attention to are things like the pressure specs on the plate (higher usually indicates a heavier clutch feel, and a higher preloaded clamping force generally means more stress on your crank's thrust bearings.... VERY bad if you're one of those people who compulsively holds the clutch in while in neutral.)
Also, is is spring loaded or non-springed? Springed clutches are designed with springs built into the actual clutch being in that the main idea is to reduce driveline shock and improve driver feel.
Also, what type of construction method did they use? For a street clutch full face, or segmented/windowed clutch design should be used. Stay away from the "puck" clutches for now.
Also, if you want stock feel you'll want an organic material. But if you'd like it a little grabbier go for kevlar or carbon/kevlar.
Oh and "stages" are just a manufacturers gimmick.