This paper represents the third piece in our ongoing lag-time measurement of solubilities and molecular diffusivities in Room Temperature Ionic Liquids (RTILs) by class. Like our previous work with imidazolium- and phosphonium-based ionic liquids, we will report diffusivities over a large range of viscosities and develop a predictive diffusivity correlation. The ammonium-RTILs used, in this study (>10 in total), include cations with both N-alkyl groups and branched alkyl groups. In addition, we will report on a number of RTILs derived from quaternary ammonium surfactants. These surfactant-derived RTILs offer a relatively inexpensive alternative to imidazolium-based RTILs. Therefore, we will compare and contrast the thermodynamic (solubility) and transport (diffusivities) phenomena in these ammonium-based RTILs with both imidazolium- and phosphonium-RTILs in the context of being working fluids in a chemical process. The gases used in this study (nine in total) include carbon dioxide, nitrogen, oxygen, methane, ethylene, propylene, butane, 1-butylene, and 1-3-butadiene. Since this will be the first introduction of some of these surfactant-derived RTILs, we will also discuss trends observed in their melting points and/or glass transition temperatures with variations in the cation. Other physical properties measured will include densities, viscosities, and surface tensions.