A brief review of the basics of the Clifford $ Cl ( 5, C ) $ Unified Gauge Field Theory formulation of Conformal Gravity and $ U (4) \times U (4) \times U(4) $ Yang-Mills in $ 4D$ is presented. A physically relevant subgroup is $ SU (2, 2) \times SU (4)_C \times SU (4)_L \times SU (4)_R $ and which is compatible with the Coleman-Mandula theorem (in the absence of a mass gap). This proposal for a Clifford Algebraic Unification of Conformal Gravity with an Extended Standard Model deals mainly with models of $four$ generations of fermions. Mirror fermions can be incorporated as well. Whether these mirror fermions are dark matter candidates is an open question. There are also residual $U(1)$ groups within this Clifford group unification scheme that should play an important in Cosmology in connection to dark matter particles coupled to gravity via a Bimetric extension of General Relativity. Other four generation scenarios based on $ Cl (6,R), Cl (8,R) $ algebras, Supersymmetric Field Theories and Quaternions are discussed.