Seeing how the Pacers are far from being a playoff caliber team, I wouldn't trade for anyone older than him. So using that criteria, I would go after one of the following:
What people don't realize is that Danny isn't even that young for this league--his current age of 25 yrs makes him only one year younger than the average NBA player. Sure, he's having a break out season, but almost every 2/3 reaches a similar offensive peak at that age! Michael Jordan, Reggie Miller, Paul Pierce, Tracy McGrady, and Joe Johnson are a few examples. Just look at the numbers and you'll see that a lot of these guys have career scoring years at that age. I'm not knocking Danny, I just think his future value may be a little inflated based on how he is performing now, and while he will be a star player for many years to come he probably won't top this season. That's why I would ONLY trade him for a younger player who hasn't reached his zenith yet.