I'm really high on Cousins, his big pitfall last season was his ridiculous 4.1 fouls a game, which limited his minutes. They wanted him out there, but he put himself on the bench. Another potential sleeper is Ed davis, he'll get all the minutes he wants on a lack lustre Raps squad. And it might be worth drafting Greg Oden with your final pick, its his contract year, and if he wants any type of money he'll have to pull it together this season.
There will be a lot of change in sleeper value or general player value from now until the season opener. I'd suggest keeping a tab on the latest trades, most sleepers are those that did not recieve minutes last season but will be given starter minutes this season.