I am a newbie to posting though I've lurked on the forum for years.

I have an upcoming trip that is:
IAH>LAS
LAS>SFO
SFO>IAH

This is pricing anywhere from $450-500 so I'd like to consider using points or miles. I've never attempted a multi-city trip using miles and would love some advice on if this is possible.

I have the following "stock" at my disposal:
Delta 138k
Continental 97k
AmEx Membership Rewards 94k
Qatar Airways 60k

The closest way I can find to do a multi-destination trip would be to use the AmEx points, but that's $0.01/point which is not a great deal.

Any suggestions?

Thanks!