A new formulation of the partial element equivalent circuit (PEEC) is proposed that is well suited to be used along with fast Fourier transform (FFT)-based acceleration techniques. FFT-based techniques are used in conjunction with iterative solvers to accelerate matrix-vector products. Despite the significant memory saving and computational time reduction, these techniques may suffer at high frequencies due to the fine voxelization that they require. In this work, a new surface impedance-based formulation is presented and a novel preconditioner is proposed. Both contributions allow the frequency range of applicability of the FFT-accelerated PEEC method to be extended up to the gigahertz range. The accuracy and efficiency of the proposed solver are demonstrated by applying the proposed modeling strategy to a toy-problem and real-world structures comprising a printed circuit board and a transistor package, involving millions of unknowns.