I think Walt has to make a deal to bolster the front end of the Reds rotation. It has been 15 years since the Reds last playoff, 11 years since the Reds last sniffed the playoffs. Walt is good enough at his job to make a trade and bring in a top notch pitcher without gutting the entire farms system.
Even if Walt needs to give up a lot of the Reds system I still think that the core of the Reds team is youthful. Guys who figure to be in the long term future are Votto, Phillips, Stubbs, Bruce, Leake, Cueto, Bailey, and Chapman all have youth on their side. You can build a team around Votto in the 3 hole similar to what StL has down with Pujols. A trade for Lee may hurt the Reds on the farm in the very near future, but Walt will also be able to replenish that with at least 2 early picks in next years MLB draft.