Let $X$ be a projective variety over $\mathbb{C}$. If $L$ is an ample line bundle, then $h_L$ denotes the Hilbert polynomial.

Is it true that, if $L$ and $L'$ are ample line bundles which are equal in the Neron-Severi group, then $h_L = h_{L'}$?

Does this imply, together with finite generation of Neron-Severi groups, that the set of polynomials $\{h_L \ | \ L $ ample line bundle on $X \}$ is finite?

Can anyone recommend a text (book or article) in which these things are explained (to some extent)?