Speedlite series flashguns

[400dabuser]

are all of them compatible with the Canon 400d?

and what are the main differences between the 430ex and the 580ex

does the 430ex have an wireless tranx and receiver?

[tim]

Yes.
Features and power (only one stop).
No Canon cameras do.

Have a read of the FAQs, they'll answer almost all of your questions.