Besides Posey and Nocioni, some other possible small forwards the C's could trade Scal and T.A. for that have less than desirable contracts (because of the contract length) but would fit well on this team, in order:
Shane Battier (2 years)
Stephen Jackson (4 years left)
Gerald Wallace(3 years left) (need to add Giddens and Pruitt)
Corey Maggette (4 years left) (need to add Walker and Pruitt)
Jackson would be the most realistic since he has four years left. I think he would be a great fit with the C's too. I don't see the ownership willing to pull the trigger on it though.
The only one of those we have a chance of getting is Maggette and he's not worth the money we'd have to pay him.
Wallace and Battier are both really valuable players (yes, Gerald Wallace is very valuable), especially for their defensive abilities.
Jackson is the captain of the Warriors, if I'm not mistaken. They are a very young team and they'd have to be really stupid to remove whatever veteran leadership they have going there. They're not trading him.
Veteran leadership on a mostly young team is also why I think Shane is definitely staying in Houston. Even if they aren't contenders they need him for his intensity, maturity, and mentoring ability.