Houston could do a deal like:
http://espn.go.com/nba/tradeMachine/?tradeId=bb9fhj9Where Robinson, Jones, Delfino & Motiejunas are moved to Atlanta for Smith. For those kind of young assets Houston could probably get their pick back off Atlanta for this year as well because it's such a rich offer for Smith who they could sign for free in the summer.
That would leave Houston's salary, after they turn down Garcia's option and without Smith's salary at $33,017,707. Smith's 1st year of a new $97.5 m 5 year deal with roughly $17m in the 1st year takes Houston all the way up to $50m but with Asik on the payroll.
Houston would have plenty of offers for Asik if it came to Howard wanting to sign for Houston in the summer as a free agent. Howard and Smith could both sign for Houston long term in the summer. Would be a fantastic young team on paper:
Lin
Harden
Chandler
Smith
Howard