DC current sensing, set threshhold curent @ 1A, 2A, etc. before action taken

I'm planning a simple multi-input 24 volt DC current sonsor project. My goal is to have 2-4 inputs, with a current threshhold level setting for each input. When the current exceeds a preset level a piezo sounder and indicator LED will be activated, etc..

I was planning to use and ordered a few Allegro ACS712 current sensing PCB modules (like: http://www.pololu.com/product/1187/resources, after reading about a current meter project using a similar board. I couldn't find any examples of sensing, setting, and acting on a certain current level however. I have simple transistor current sensing circuits, but they trip at 25ma.

Is the Allegro ACS712 a good starting point? Anything better? Any suggestions appreciated.