Last I checked, there were few life threatening characteristics of paper targets ....
OP, how much are you willing to spend ? I can only speak from personal experience, but here are the ones I own based on my hours of research.
Norinco cqa 14.5" $699
- - Best bang for the buck IMO. I have thousand of rounds down range with no issues. Don't expect a glamorous AR, as this Chinese built firearm certainly lacks the "###y" factor of most US built AR's .
Daniel Defense MK18 & M4v1 ~ $1,800
- - I am a DD fan boy, so slightly biased - but this will certainly IMO be your best bang for buck "quality" AR
I would also suggest looking into Armalite, Colt and Noveski if you have the budget to accommodate such beauties.
Of course there are countless other options available but I will only speak of my personal choices.
Here is a good place to start your research... I spent months researching before buying my first AR

- get comfy !!
http://www.canadiangunnutz.com/forum/forumdisplay.php?69-Black-and-Green-Rifles