Medicine ball - rubber, leather or double-handed?

[qwert]

Hi. I'm gonna take brown bomber's advice and buy a 4 kg ball, but I was wondering if anyone could recommend what material ball I should get? I couldn't find any tips on google. I'm gonna be using it for plyometrics and core work. Is there a disadvantage in getting a double handed one? They're all about the same price on amazon.

Thanks.