  We propose a differential representation for the operators satisfying the
q-mutation relation $BB^\dagger-q B^\dagger B=\1$ which generalizes a recent
result by Eremin and Meldianov, and we discuss in detail this choice in the
limit $q\to1$. Further, we build up non-linear and Gazeau-Klauder coherent
states associated to the free quonic hamiltonian $h_1=B^\dagger B$. Finally we
construct almost isospectrals quonic hamiltonians adopting the results on
intertwining operators recently proposed by the author.
