Different Slow-light systems have been discussed and developed as a powerful tool to reduce the group velocity of optical signals during the last years. It has enjoyed much recent interest because of the potential system applications in optical telecommunication and information systems. Especially the nonlinear effect of stimulated Brillouin scattering (SBS) has become important for fiber based Slow-light systems. But, the SBS also has two challenges. First, the maximum time delay is limited due to the saturation of the Brillouin amplification process and second, the delay of the pulses is accompanied by pulse distortions (pulse shape broadening). For these aspects the shape of the Brillouin spectrum is of special interest. In this article a system is presented which allows the optimisation of the Brillouin spectrum. Simulations and first measurements show how the time delay can be enhanced with a simultaneous reduction of the pulse distortions.