Hi, I am new to this forum and also new to this game. Currently I had few strike balls on hand already. What I am lacking is a spare ball. I had read around about having plastic ball coverstock and such or UT coverstock.

I'll just want to know.. What should I look out for, for a spare ball?

Does it really must be a plastic ball?

If I really want a UT ball like example Storm Pitch Black or Mix, what should I do to the ball?? Drill for lesser flare? Make it to hook lesser?

I understand that there are also other thread talking about UT vs plastic, but I am so new to this sports that I don't really understand all the terms used. Sorry. So please go easy on technical terms.

Thank you people!! 

Yes, urethane can hook, but it is about predictability, not a little bit of hook.  Urethane will always hook a little bit, unless you really try to make it go dead straight.  Polyester will sometimes hook, and sometimes go dead straight off the same release.  If you are a guy who totally throws rockets at your spares with a super flat hand, it makes little difference which ball you throw.  As an old guy who doesn't throw hard at his spares, I like to have a small, and predictable hook on every ball I throw, which I don't get with polyester.