Finding the IC for my project?

how do I find the ic to best fit my project? 

I need to build a circuit to supplement a larger project. my circuit needs to capture analog voice audio from its input, convert it to a digital format (ie mp3 or wma), and save to a usb thumb drive. it needs to create  a new file every time the system is powered on and save this file when the system is shut down.

I find many diffrent places to get IC chips and information on them but am having a difficult time searching for one like that.

any ideas on how to go about looking for a solution?

Thanks!!

You want an mp3 codec, they are readily available, Try Sparkfun and Adafruit, they have a few, if you need to have a play. If you want to go open source, Ogg vorbis codecs are cheaper, no license fee.
You will need a micro for support,
cheers,
Richard