I don't know how many wires, but I imagine 1/2 of them go to the ECU, and 1/2 come from the ECU. As an interceptor, of course. So it makes sense that a single connector per wiring bunch could do it. My suggestion would be to do it yourself (it will still be PRO...but you can verify it was done right), one pin at a time. You cut a wire that you know you need to cut, and pull a little insulation off each side. Then crimp or solder on the pin. Then slide the pin in the connector, and it is complete on that side. Do the other side, one at a time again...you've got it in no time. Maybe an hour with a solder iron, if that? I recommend the Butane powered soldering irons available at Radio Shack. I've got a few of them, and they work in any condition.
Once you have the factory wiring pinned out, and wired properly, then you can reconnect the halves together again and verify perfect function as if you've not touched anything. From here, you can install the pins to the connector on the Xede harness, not even being installed in the car. From here, its a matter of truly plug-and-play.