Trevorlane, XLR cables cost a bit more than RCAs, and for components that have RCA outs, you'll have to buy RCA/XLR adaptors. People like the ones that Balanced Audio Technology sells, but they're not cheap. Just some hidden costs of going balanced. You also do better with an all balanced system if you go that way.
I think conventional wisdom would say, XLRs are better than RCAs, all else being equal, but you should really shop with an eye on the component not the connectors. The output jack type won't change the fundamental sound of the component. Hope that helps.