The Elinchrom strobes you are looking at don't support any vendor specific protocols, and the Elinchrom Skyport Transceivers do essentially the same as modern ebay triggers like the Yongnuos: wirelessly forward the flash trigger signal. This leaves you with three options:
[list type=decimal]
[*]Use your 430EX in manual mode to optically trigger the Elinchrom. This requires that your 430EX stays on the camera hotshoe. You can not use E-TTL because it uses a preflash which would prematurely trigger your Elinchrom's optical slave trigger. This method does not require additional investments.
[*]Get Yongnuo triggers (e.g. one transmitter and two receivers) to fire both the Elinchrom and the 430EX. As with the previous method, your 430EX must be set to manual mode. The Yongnuo receivers can be directly attached to the hotshoe of your 430EX, and they come with the necessary cables to connect them to your Elinchrom. You can not use the Elinchrom Skyport set in this scenario, AFAIK it is not compatible with the Yongnuos.
[*]Get a separate Elinchrom Skyport receiver and the adapter suggested by m and use these to trigger your 430EX in manual mode. Note, that one Elinchrom Skyport receiver likely costs more than the whole Yongnuo set, but chances are that the Elinchrom Skyports are more reliable, better in build quality and have better range. YMMV.
[/list]
When I got my first Elinchrom, I already had the Yongnuos, so I chose method 2, and it worked reasonably well. I did, however, notice very quickly, that my Metz 48 was so much weaker than the Elinchrom, that it was nearly pointless to use it at all, so I bought two very cheap 100 Ws studio flashes soon after.
