The novel and sensitive In-Gas Laser Ionization Spectroscopy (IGLIS) technique enables high-precision laser spectroscopy of the heaviest elements and isotopes very far from stability that are produced in fusion-evaporation reactions at in-flight separators. Powerful and dedicated laser systems are required in these facilities to realize in-gas jet laser spectroscopy with optimal spectral resolution and efficiency. The performance with respect to the requirements for IGLIS studies at the low energy front-end of the Super Separator Spectrometer (S3) at GANIL, France, of Dye and Ti:sapphire laser systems is investigated. In addition, a number of specific experimental cases on key isotopes of the elements Ag, Sn, Ac, and No are discussed in detail.