Dude, just write "Nike Strike ball" in Google and it will give you loads of info. Doesn't matter if it's the T90 or the Premier League model, because it's the SAME ball, just a different design. And no, it isn't slippy, the grip is actually quite good, which I already wrote in my post above.
I don't recommend the Saber model at all! I have it and it's slippery as hell. Maybe later on when you wear out the first layer, but still wouldn't risk it.
Seriously, just get some rubber ball (Kube, Urbanball, etc.) or any of the cheap balls from Adidas (Glider) or Nike (Strike). One more that I can recommend: Adidas Top Training balls. Something between the cheap ball and the matchball.
One question: do you care more about getting a good ball for yourself or just getting the same thing the freestylers you look up to use?
P.S. Just typed in "Nike Strike ball" in the ebay search and it gave me 46 results. How on Earth did you manage to not find it? lol