The Red Sox tend to look for upside with their first round picks. Benintendi is the only pick in recent years that really fits as a "floor over ceiling" prospect and even he had a high ceiling. As a result, I think the Sox look toward Houck.
Baseball America projects Houck to the Sox at 24, and a few other sources have him in a similar range. Houck is a college pitcher, which would denote a shift in philosophy for the Sox, but given that the Sox selected a college hitter in Benintendi, I think they may still make the decision to target Houck, a righty with a strong fastball and a developing sinker that scouts really like.
Houck had a poor SEC tournament at Missouri, and his stock has been falling as a result. Most still have him going a few slots ahead of Boston, but I think he ends up here. It wouldn't be the first time that the Sox landed a player later than expected in the first round (Groome, Chavis).