Canon 600EX-RT and 5D Mark III - question about wireless connectivity

Dear Experts...

Do we need an STE-3 to fire 1x600EX-RT wirelessly from a 5D MkIII ? From the 5D MK III manual (page 193), it seems like it is possible to use either optical or wireless. So in this case the STE-3 would not be necessary. Is that a correct assumption ?

What if I also need to fire a 430EX along with the 600EX-RT (both using full TTL) ? Do I need a set of pocket wizards ? I'm planning to buy 2 flashes and start exploring flash photography. I prefer stick with Canon flashes, be cost effective (:-) ) but not to be limited by the hardware. Either way it goes, it will be a large investiment as I'm not planning to make any money from this.

Thanks for any advice or comments. Cheers.