i used to scratch alot but i never bothered buying scratch records.
if you have origin unknown - truly one
there is a good hi hat kinda sound at the intro good for scratching...its only good for the little quick scratches though as its a short sample.
i also had chase and status - sirens remix which had an acapella on the other side which is good for scratching.
basically any acapella is good for scratchin pretty much...its better if the person has a higher pitch voice though