Ab initio averaged relativistic effective core potentials (AREP), Spin-orbit (so) operators, and valence basis sets are reported for the elements Fr through Pu in the form of expansions in Gaussian-type functions. Gaussian basis sets with expansion coefficients for the low-energy states of each atom are given. Atomic orbital energies calculated under the j-j coupling scheme within the self-consistent field approximation and employing the AREP's in their unaveraged form (REP's) agree to within 10% of orbital energies due to numerical all-electron Dirac-Fock calculations. The accuracy of the AREP's and so operators is also shown to be good through comparisons of calculated so splitting energies with all-electron Dirac-Fock results.