Pretty much any camera will work. The lighting & shadows are more important than the camera. I made my own green screen for under $20. I bought 8 meters of a good green cloth, sewed it into a 4 m by 3 m rectangle. There is one seam down the middle but that has never been an issue with the chroma key. I bought 2 light fixtures and 2 umbrellas, with a silver "metallic" inside, as light diffusers. I do not have a frame for the cloth, but just use clips to hold it to the curtain rod on our front porch. Sometimes I drape it on the floor, depending on the need.
I made sure the cloth was not too shiny, and no patterns. Smooth, nicely green, not neon, and keep the shadows off of it.
