Thanks for all your suggestions. I'm leaning towards Scott's suggestion on just getting a second 550 or 420. There are several reasons why.
1) Portability
2) I like the idea of having a backup flash unit
3) Wireless
4) Good scalability later on if I want to add a third unit.
5) Retain ETTL
6) Later I plan to buy a second film based camera so I can keep the second flash on it.
I think the extra cost for the second flash seem to be really worth it. So now that I have a couple cool flash gun brackets to choose from, I just need to select an umbrella and stand and I should be good to go. Thanks allot guys.
What size unbrella would you suggest? My daughter is 36 inches tall.
wow, im shocked. 



