You might want to avoid strong cover/core combinations (ie Theory, Cell, Mutant Cell which are all solid coverstocks). I would be looking at pearlized covers, or possibly weaker polished solids (nomad). You might also want to drill the ball with a longer pin to pap distance to increase the amount of length/backend. Cell Pearl, Mutant Cell Pearl, Nomad Solid, Nomad Dagger, Storm Anarchy, Virtual Energy, Infinite Theory (yet to be released) might all be options that can be drilled to give you better length and strong backend.