If I may ask, do you already have dedicated lines? If so, fine, worry about a power cord so long as you don't spend too much (I like French_fries' advice).
But if you don't have dedicated lines, don't even think about doing anything else related to power in your system until you get them. To get two lines put in (one for amps, one for sources) in most houses costs less than $500. This is not only far more important than power cords, in most cases it is the biggest bang for buck improvement one can ever make to one's system.
