From a quick look at the Elinchrom site it looks like their current units work on a 5 volt trigger. That's safe for the Canon cameras. Check the specific one you're interested in at
http://www.elinchrom.com/
I've tried the Hama cable and it worked fine. The (potential) problems were the same as always; standard pc connectors come loose at precisely the wrong moment and people trip over cables with a frequency directly proportional to both the cost of the equipment connected to them and their ability to sue for damages.