I've purchased the long run RCA cables from MonoPrice and can vouch for both their quality and their "heartiness". For the price, they are an unbeatable value.

You might also consider linking a few smaller RCA cables, if yo've got them laying around, with some RCA links (AXIOM sells them, in fact). You won't notice any decrease inquality, but can save a few bucks and feel good about using exisitng cables rather than buying brand new ones.