I am looking at getting an external flash for my Canon EOS 40D & would like to know people's opinions on what to look at but also at a decent price range as well.

Should I also look at getting a defuser, as well as a bounce card ?

Also, is it just worth getting a 'rip off' flash off of eBay like a Nissin or a Yongnu ? I'm not right into using a flash at the moment, but it is something I would like to play & experiment more with.