I think that would be a little less power then you want. Have a look at something like this: http://www.elfa.se/pdf/73/734/07347024.pdf
A LM1876, costs about $10US and gives you 2x20W at 8ohm. THD 0.08% at 15W.
At least the specs look good, havn't used it myself.

Or you could just buy a small amplifier kit, gives you all the components and a pcb for it...

// Jonathan