Gohtalo

well the stipend given to Phd students differs from one department to another. In science department (physics, Bio, chem etc), they give higher stipend than in other liberal arts program..(I don;t know why).....for them it is around 20,000-25000 a year...for others it is little less....but whatever it is ...it is enough...coz you don't have to pay for tuition....some of my friends have family to look after and the stipend they get from our department is enough for the family..

Since AI (Associate Instructor) has more work to do they give little bit more to the AIs..

Well this is basically more or less same  in most of the schools..it depends on the program you are applying...I don;t know for sure... but I think GRE scores are important to get funding from the school..anyways each school has a different criteria and some might give more preference to GRE scores and others might give to GPA..

I agree with Nepal ko chora.....PrasantaJi , I think u should talk to the professor in your department. They might be able to help you with the funding.

Goodluck!!!