Well there's nothing peculiar about the 803's so really any cable that's 12 gauge, give or take, will faithfully send the signal. If you don't like stuff like HD or Sound King, you can look into KnuKonceptz or some of the Canare stuff and there's even some 'relatively' inexpensive wire from IXOS. The layered pricing structure that many companies have bears no relationship to tangible audible improvements.
So IMO 12 gauge Megacable from Radio Shack should work great with your speakers.
And as far as science not knowing everything about wire, sorry folks but wire just isn't that complicated as far as the consumer amp-to-speaker question. We're not talking Cray supercomputers or planetary robotic probes here.