HELP!!!

[chasmars]

I downloaded shoutcast, the net media tools, and the DSP plugin, but I CAN'T get a quality on my streams above 56 kbps! It won't let me select it from the list. I know that I need to buy a new decoder, but I don't know what I should get! Could someone please give me detailed instructions on how to buy and install and new codec? Any help would be greatly appreciated,
CS Marshall