The problem considered in this paper is the design and analysis of implementable architectures for semi-active suspensions characterized by a regulation of both damping and stiffness coefficients. The first contribution of this paper is the introduction of a suspension architecture that makes possible the emulation of the behavior of an ideal suspension with variable spring by using only shock absorbers. Taking into account the comfort objective, a full analysis on the advantages and drawbacks of this kind of suspension is provided. This paper proposes a very simple novel comfort-oriented stiffness-damping control algorithm to highlight the benefits provided by this system.