Yes, jobslinger is where you will see who is in what area. But as someone else posted in antoher thread, signing up with all those companies is a right of passage. The most important thing here is that contracts change, but you will be in the databse forever (unless we talking Market Force or Certified but that is another thread LOL) so when they do get work in your area, you should get contacted.
Even though it means nothing, I think it's worth the minimal expense to get silver certified. Once I did that I had more emails coming in. A few companies claim to offer to certified shoppers first.
Build a rapport with schedulers, do them a favor (not just self-assign shops), and never ever be late or bail on a shop. You will find yourself getting more work.