There is no "good option". The best thing we can do is just keep our noses out of it and let them work it out for themselves. Yes, this will take many, many years.
However, the evidence is growing that pro-Assad forces used chemical weapons. President Obama said that was a "red-line", and I have to agree with him on that point. Whether he ordered the strikes himself or not, he is responsible for them. Someone must do "something" to make sure these weapons are not used again.
The interesting thing is that the use of these weapons proved ineffective in "stopping" the rebels, since the areas attacked were also shelled shortly thereafter and yet they still remain under rebel control.
Bearing in mind that any response is NOT for regime change but simply for the use of chemical weapons, I would prefer that any response comes from the UNSC. That appears to be unlikely, since Russia and China will probably veto any action. My next choice would be a response from NATO. With the recent British Parliament vote, that seems unlikely also. My understanding is that most MP's were voting to delay response until more information was known - which I can certainly understand. I also have the impression that most voting "No" were expecting another vote, which now seems unlikely as the PM seems willing to block any further action like a petulant child. But that is his choice and his maneuvering.
Now, there is a side of this that no one seems to have considered. Much has been made of the fact that one of the rebel factions is al Qaeda related. If the perception is that the US helped them out, this might take some of the teeth out of anti-US rhetoric in some of the organizations. I am only talking perception. I am not recommending we do that. In fact, my recommendation is that we maintain the perception that we are being neutral, and do everything we can to maintain that perception.