I've been searching for I-docks, but i can't find one for under $100. Seems like there should be a cheap, quick fix.
Here is the Apple universal dock that comes with a remote:
http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore.woa/wa/RSLID?mco=31188AB7&fnode=home/shop_ipod/ipod_accessories/cables_docks&nplm=MB125G/A
Here is a stereo cable:
http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore.woa/wa/RSLID?mco=DB33510D&fnode=home/shop_ipod/ipod_accessories/cables_docks&nplm=TN778LL/A
You can also buy these for cheap at any electronic store.
Here is everything else:
http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore.woa/wa/RSLID?nnmm=browse&mco=FB301BBD&node=home/shop_ipod/ipod_accessories/cables_docks
Any specific iPod dock has a audio out plug on the back of it so you can use a stereo cord to your speakers.