No. I'd go with all Canon. Wireless flash can be a little tricky and if you stick with all Canon gear you'll get maximum compatibility between all the components. I'd be very hesitatnt to throw third party flashes or controllers into the setup. If you do that and something doesn't work, who do you blame (and who will help you out)?
I'm happy to use 3rd party remote releases, lens hoods, filters, lens caps etc. which aren't technically complex devices that have to communicate with the camera via a technically complex interface. However for wireless flash systems I'd stick with Canon.
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Canon Speedlite 580EX II is pretty hard to beat. Though it's about $200 more than the STE2, I still think it's a better deal since you get all the flash functions thrown in as well as a master controller.