ARC gears & B&W speaker

Hi, I have ARC VT100 MkII amp, ARC LS15 preamp, ARC CD2 cd player, B&W N803 speaker. I'm using MIT balance interconnects between my gears and MIT T2 bi-wire speaker cable. I would like to try new speaker cables for my system, anyone has any suggestions?? I like the warm sounding of copper cables. Thank you.