Depending on state laws, non-compete agreements generally are not worth a lot. It is my understanding that they can't keep you from earning a living, no matter what you sign. HOWEVER, I am not a lawyer, and I would suggest that you contact one with this specialty for your state, as laws vary from state-to-state, and get a reading for your situation.
One thing to do is narrow down and be as specific as possible as to whom you'd be restricted from working for.
I would be hesitant to do this, as you may be digging yourself a hole that you don't need to. In the final analysis, it would be up to a court to decide this issue, and you don't want to screw up the latitude the judge may have in making a decision by having pre-existing understandings and agreements outside of and in addition to the standard non-compete agreement. However, it is unlikely to ever get to court.