Best interconnects for CJ amp and preamp?

I recently bought an MV-60 amp and a PV-12 preamp. They are paired with Von Schweikert VR2s and a Rega Apollo Cd player. I made my own speaker wires with multiple strands of CAT-5 cable (i.e. copper) - no spades on the ends. I like the sound, it is neutral to warmish, easy to listen to, no fatigue. Recently, I added some Roller Block Juniors for feet, and they seem to add some detail and make the sound less warm. The interconnect between the amp and preamp is old, Monster Cable that I had lying around. I prefer neutrality in a system, but if I leaned toward changing the sound, I'd opt for adding a little more livier sound. Any recommendations for used, or new - with an in-home trial? Thank you.