on ebay, there is often mil-spec silver clad wire with teflon insulation, usually very cheap. Or get some of the shielded silver clad teflon two conductor cable. Neutrik makes a decent inexpensive rca connector or if you feel like spending more, bullet plugs are very good.
Of course, you can purchase many of the higher end commercial IC wires in bulk cable form and you can buy the WBT nextgen connectors. But you'll spend a lot of money and the DIY ICs have no resale value so you might be better off buying commercial cables if you plan to upgrade at some point.
VHaudio sells the pulsar wire in bulk for DIY and has many very good connector options.