seriously any 18 guage wire will do fine. you're running such short distances that there will be no real world difference between $20 a foot super secret special wire and $.02 a foot lamp cord from HD....
if you have any speaker wire in the 16-18 gauge variety from running your HT or what not, just use that. otherwise hit up radio shack or home depot and grab a few feet and call it a day. I've built more than my fair share of speakers and it's pretty much scientifically impossible to tell the different wires affects apart