The conditions for achieving the laser acceleration of quasi-monochromatic ion bunches with present-day, fs laser systems are theoretically discussed. The study suggests the possibility of achieving quasi-monochromaticity via irradiation of double-layer, nano-structured foils and the conjecture is numerically confirmed by means of two dimensional, Particle-In-Cell (PIC) simulations. A feasible setup in order to experimentally validate this approach is thus proposed.