We introduce a classification scheme for  parton distribution models and we model
generalized parton distributions (GPDs), their form factors, and parton distribution
functions (PDFs), integrated and  unintegrated ones, in terms of unintegrated double
distributions that are obtained from the parton number conserved overlap of
effective light-cone wave functions.  For a so-called "spherical" model we present
general expressions for all twist-two related non-perturbative quantities in terms
of one effective light-cone wave function, including chiral-odd GPDs. We also
discuss the Regge improvement of such quark models from the $s$-channel point of
view and study the relations between zero-skewness GPDs and unintegrated PDFs on a
more general ground.