After taking the photos, the next step was bringing them into Maya and start matching the camera angle and the lighting. The photo of the cube is used to match the camera inside of Maya, making sure to use the same focal length as you did when taking the photo. Then the grey ball photo is used to match the lighting, trying the brightness the same as well as the shape of the shadow.
Wireframe overlay of the cube to match the camera perspective, with a 70mm focal length.
The photo above on the left is my reference image of the grey ball, the image in the center is my lighting match of the grey ball in Maya, then my light settings on the right. Right now I think the shape of the shadow on the ground as well as on the ball is working, although I think the shadow on the ball could be softer. Also, the underside of the ball is a bit dark, so getting the bounce light from the ground in there will be important.
For the HDR, right now I am using a sphere with a surface shader as the dome around my scene. I think it would be worth trying the aiSkyDome as well, to see how it might be different. There are also some color management issues that need to be addressed as well.
I also did a block out of the rolling ball animation to get a feel of how the ball should move through the space.