Interconnect or Speaker Cable in HT

I'm sure you audio Guru's out there knew this one at birth, but ... Is is better to locate the M200 centrally and then run a long speaker cable, or run a long interconnect (through the wall, under the floor, up the wall ...) to a M200 located near the speaker? If the latter, then what is a cost effective material for making my own interconnect?

Thanks

Conventional wisdom states that interconnects should be shorter, speaker cables longer. It has to do with things like impedence and pico-farrads/foot. You can get preamps that can drive long interconnects well, but they are the exception.