Hi,
1. For job hunting agency specialize in accounting, have you tried Accountemps?
2. I would also recommend agencies in your local area that specialize in government jobs. Once you get in the job, find a way to settle yourself permanently in the government. The government will always land you a working permit. (Although the pay must be slightly less.)
3. I would say unless you have a good connection in a small CPA firm. Otherwise, it's very hard for a small CPA firm to get you a working paper to stay. Maybe you can also try law firms that have a CPA. A law firm will make the path to a working paper slightly easy.
4. You should also try to use your school connection. Talk to any professors that remember your name and express to them your difficulty, they might be able to land you a job somewhere! If they can't land you a job, they might be able to get you a tutor position and eventually you become a professor (and start from there, you turn your career somewhere.)
5. Never miss out any college / school alumni internship opportunity. Any internship with the big firm means you will stay with them after internship, and you will also permanently solve your working paper problem.
These are based on my personal and friend's experience. My friend also use working paper and doesn't have a green card.
New York - NYC
Passed CPA Exam (11/2014)
In search for a position in NYC that will fulfills the license requirement.