Yes, it would be a custom build, so just add in the notes when you place your order which option you want, either the hard wired EC5 (nothing extra) or 4mm bullets with the adapter ($4 extra).
On another note, you could use the 12v and it would work just fine with the PL6, but I would suggest, if you have the funds, to upgrade to the 24v power supply to get the most out of the PL6. You may not need it now, but possibly later on down the road...