We propose to study the evolution of the ground state vortex lattice (VL) phase diagram and the metastable VL phases in MgB2, as the non-local vortex-vortex interactions are modified by doping with non-magnetic or magnetic elements.Previously, we have discovered that MgB2 exhibits an unprecedented degree of well-ordered, metastable VL phases and shown conclusively shown that the metastability is not due to vortex pinning. While the mechanism responsible for the metastability is not resolved, we speculate that it is due to VL domain jamming.The VL configuration depends sensitively on both the Fermi surface anisotropy and mean free path of the host superconductor, and in the case of MgB2 there is an additional two-band effect.We focus on modifying the vortex-vortex interaction by doping by either non-magnetic carbon on the boron site or magnetic manganese on the magnesium site. Both are expected to affect the ground state VL phase diagram. These studies will provide a better understanding of the VL in situations where several competing effects are present. Secondly, we will begin studies of how the doping affects the kinetics of the metastable VL phase.