Swisher was just traded for Wilson Betemit and Jeff Marquez. The market seems to have been established (its not like he's played a game to change his value since then) and would suggest that the Reds wouldn't have to deal a stud to get him. I think he's a reasonable target that should not require a centerpiece to acquire. I'd guess a couple of guys to re-inforce some weak areas on the Yankee roster would do it. David Weathers seems like the ideal choice since it addresses a yankee need, holds the Reds payroll to a reasonable number and the team has a number of candidates to backfill for the pen.
Seems like an old fashioned baseball trade where two teams deal excess pieces to address needs with the money (at least for 2009) being roughly equal. The Reds would only take on about $1 Million to this year's budget.