have a look at Willys Electronics. There you will find in kit from audio amps in high and low wattage.
Roll your own Dude.... Try this site:
http://runoffgroove.com/
They have instructions to make several suitable amps..... and many are quite easy...
Radio Shack has a mini amp for about 20.00 bucks, but with a 386 chip and a handful of parts, you can build one in a bout an hour.
Lewis