I agree that maybe a stinger, tornado and a V2 would be a nice starting point. I bowl strictly Ebonite, currently:
V2 Strong
V2 Clean (my over-all favourite)
V2 Sweet (on order, to be drilled in a few days)
PrimeTime Pearl
Matrix Tps (old but reliable)
Gemstone (mostly for the 10 pin)
If you're going to carry a spare ball it would probably have to be a Maxim since the Gems are not made anymore. Any of the Vortex series is good, the Clean or Sweet probably being the better choice if you're only going to carry one Vortex. I've primarily gone to all polished balls, the strong being the only dull ball I carry.
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Ebonite Rules