Not an option, unfortunately. He's got WMD, remember? You don't just "take out" an enemy armed with WMD. Not unless you want to die, that is.
He does not have a delivery system to get them to the US unless he straps them to Hahakmed and has him unleash them. He has already used Sarin on our troops in the Gulf and Bush the Elder did nothing about it so why should Bush the Younger be any different?
Killing the Hussein line of succession would eliminate Iraq as a threat. Quick, painless, and you aren't screwing around with the UN.