Weight tolerance is also important. There has been a lot of advertizing hype on spine tolerance, but it seems to me, that if you have a set of arrows within .001" and +/- 1 grain the spine would be pretty close as well.
Of course if your REALLY worried about it, you can get your own spine gauge and check a dozen before you buy them (You do get them from a pro shop....right?).
As far as arrows for 3-D...with the way they score (the way MOST any archery game is scored) you get a bonus if you shoot a fat arrow (as long as your as accurate with them).
You might want to check Carbon Express CXL or Linejammer series