Sign up with every company you see listed on this forum, use some intelligence about those companies who have given some of us very bad experiences and judge for yourself. Also, just because a company doesn't have shops in your area now doesn't mean they won't get a new client at some point with plenty in your area. I'm signed up with almost 200 companies. It's hard to gauge how much per week because it's not a steady thing, more work is available in certain parts of the country and near more urban areas. I've done everything from restaurants to churches, funeral homes, insurance, zoos, landfills, retail stores, car shops, phone shops and testing sites. I'm sure I've missed a few here.
Good luck!
Her Serene Majesty, Cettie - Goat Queen of Zoltar, Sublime Empress of Her Caprine Domain