I really like the PGA2311 for volume control duties. If you want to add a bit of signal processing, you may want to look at the offerings from MiniDSP.
I've used some small, latching, signal relays for source switching in the past. Also gives a nice satisfying click when you change source. Latching is nice, as you don't have to constantly power the coils, and they retain state with no power.
Ian.