Licorice,
What I'm doing does not require an analog to digital converter. I record to the Korg MR2000s, i then transfer the data to my computer via a USB cable. You wouldnt have to do anything to your computer to get the data on there....no cards, etc.
Now then, you will need a digital to analog converter for playback. For your application, simple is better. Depending on your budget, we could all recommend our favorite USB DAC.
Buy a Korg (street price $1500 or so), plug into your Preamp's tape output, record some vinyl, transfer the files. Once the data in on your PC, the Audiogate software included with the Korg will strip out the individual tracks wherever you specify in the format you specify, then you can import into iTunes or your player of choice, enter the song info and you are done.
Then just play it through the dac you choose and you are good to go.