I have a number of subscriptions to services that should have every utterance of the phrase 'White Sox' appearing in either newspapers or blogs easily available to me. Somehow all of them missed this one.
Buried in the Daily Southtown's Cubs Notes section, which is why I didn't come across it on my own, was this tasty nugget.
There's no real reason to speculate as to who the Sox would have given up, in theory, to pull off such a trade, or even ponder whether bringing in Prior would be a good move. I find it interesting only because it shows Kenny Williams conviction to doggedly pursue top pitching, specifically through trades.