Currently a temp and don't know who to list as my former supervisors on job applications.

I need some real advice on job-hunting. I am a temp at a large corporation and have been on my current assignment for well over a year. The company I'm assigned to is saying they definitely can't hire anyone full-time for the rest of the year and won't even consider it until 2014. So, even in 2014, I have no assurances that they could bring me on as a full-time employee. There was a brief window of opportunity a few months ago, but as I was waiting for my references to complete a long, mandatory questionnaire, upper management decided to make budget cuts in my department and the opportunity evaporated.

I want to find a new, permanent full time job. My job-search skills have atrophied a bit and I am really confused about listing former supervisors on job applications.
I don't know who I should list as former supervisors on job applications. I have done PREVIOUS assignments for my current employer, a STAFFING AGENCY, ranging from 1 week to 2 1/2 months. All of my onsite supervisors from those assignments have now moved on and I seriously doubt that most of them would remember me. Also, the people from the staffing agency who placed me in every assignment, including the current one, have also moved on. I have managed to find the current companies of some former onsite supervisors, so I could theoretically list those phone numbers If I list those people as former supervisors on job applications. Should I list both categories of people as former supervisors OR just one of them? Should I list the current people at the Staffing Agency, even though ? none of them have placed me in any of my assignments? PLEASE HELP!