Going off what websites like NBADraft.net say, I'd have to say Posey. The strengths seem to be his ability to knock down the three, his effort on the defensive end, his long arms, and his overall hustle. His weaknesses seem to be his ability to drive to the basket, his mid-range game, and his ability to be a playmaker.
Sounds a lot like Posey to me.
His biggest disadvantage is that he won't have the respect from the officials that Posey had, so it may be harder for him to play the type of defense that Posey did. However, he probably will have more athleticism at his age, so it may make up for him.
To me, outside of maybe Miles, Giddens is the big sleeper on this team for next year. Walker may have more upside down the road, but I really like what Giddens could do next year.