First consider where you want to be on the 8 to get to the 9 where you are most comfortable with. Learning to play position for the ball after the next one is invaluable (beyond words).
Personally I would like a slight angle on the 8 so I can so I can draw back for the 9 but hit the rail so I don't scratch, over draw to the bottom rail etc.. I also want to play shape with a slight angle on the 8 so I don't end up on the wrong side of the 8.
With that in mind I would use just far right (inside) maybe a tip high and spin it 2 rails (if you count the bottom rail). I am coming into the 8 with a shot for so much of the way that it is hard for me not get good shape.