Hi Guys dumb question, but need to be 100% sure!

My new Canon 600D that I have coming, will do wireless multi flash with TTL metering direct from the Camera. And from what I can make out with a few quick searches is that any Canon speedlite flash will be triggered using this system. For the TTL metering only the EX flashes will work although it will also trigger the older EZ speedlites, but without the TTL metering option. Would I be right in my breakdown of the information that I have found.

Are there any Canon speedlite flashes, you think are best suited for multi off camera flash / Strobism with full TTL metering?
Any other relevant information regarding this subject more than welcome, as totally new to this line of photography. Yet to do first image that new. Also website links regarding Strobism.

Many Thanks and Happy snapping Aidy