Hi Steel

As Ilija and Paul have said, you can do what you want, including splitting your controller so that the accompaniment plays on the left and the piano on the right.

Of course, its all subjective. But I would buy the XV-88. If I wanted a good classical piano sound, I would add the XV piano card, which I think is 64MB from one Piano. For more general-purpose piano sounds, I would add the JV session board. All the controllers you mentioned are excellent, but the Roland sound library makes the difference for me. (I have a Roland XV-5080).