DH Labs has two cables that can be internally bi-wired: (A) the (14 gauge) T-14 (B) the (10-gauge) Q-10. Each has four wires separately insulated within the cable that can be used to complete the circuit on either one or two sets of binding posts. I bought mine from Jeff at Value Audio on this website. I feel comfortable recommending him. Neither are Radio Shack cheap, although both are at the 'bargain' end of high quality cabling.
