Shadowrun Combat Redux, Need help on mechanics... Options

[Diesel]

Someone a while back suggested "action figure targeting" for SR. My interpretation of this is as so: an action figure or similar model (artists models are good, IMO) of the target is procured, and placed into the correct pose. A "target ring" is then placed over wherever the attacker is targeting (essentially eliminating the called shot). The target ring looks a lot like a bullseye, with several concentric circles and six "pie slices" cut into it. The better a character shoots, the closer to the bullseye he makes it. A perfect shot goes where it's pointed, while others go wider thanks to a scatter diagram and bigger rings.

Image is here: http://www.squick.org/~diesel/hitloc.JPG (rings / model not exact, but that's the best I can do with google + Word, you can figure it out :D )

Here's the problem, I'm not sure which mechanic to use for determining hits. My first idea involved a variable TN for shooting tests, with the standard TN hitting the second ring, and +1 / +2 nailing the first / bullseye.

[Example]
TN - 2 ----- Miss!
TN - 1 ----- Outer-most ring
TN ----- Second ring
TN + 1 ----- First ring
TN + 2 ----- Bullseye!

I then realized, with damage increasing hit locations (head +2 or 3, torso +0, limbs -1 or 2 etc.) , staging would get pretty bad in some shots, so maybe a dice mechanic would be better.

[Example]
Zero successes ----- Miss!
One succ ----- Outermost
two succ ----- First
three succ ----- Second
four succ ----- Bullseye!

This system isn't close to being finished, but I'd like some opinions before I set myself in too deep.

So yeah, shoot.

And thanks for advice.

[Diesel]

I settled on the more successes = better shot. That way they're worth something, and those high dice throwers have something to work for. I'm thinking five successes = bullseye, and the head is bullseye + one ring. Keep the instant kills down, that's for sure.