If you want spell crit just because you want it, cool. However, again, if you are looking to min-max (or get the best bang for you buck), you are almost certainly better stacking +dmg over +crit. I explained why two posts above, or if you want to google there's tons of info on this subject. Bottom line is you'll get more damage/item, generally speaking, going for +dmg. Obviously just a rule-of-thumb.

Also, the 16% figure is for raiding (boss level mobs, or +3 level mobs). If you are running heroics and less, which I think describes a lot of boxers, you don't need nearly that much and it's just a waste to stack that much. This page has a chart showing you what miss chances you have based on the mobs level relative to your own. Highest mob level I've seen in a heroic is 71, so that means you need 4% to hit until you start raiding. First "raid" zone would be karazhan.