yup, done it.
I got a turbo crossmember to save rooting around with modifying the old one. a standard down pipe off the turbo, and still have the stock exhaust from there on (drinking straw size).
On advice from steve_rising_sun, I stripped the injector wiring loom off my engine, and transfered it to the new one (the japs cut through it right next to the plug anyway!!) throttle sensor plug may be different, same wires but different shape.
I also picked up an import turbo ecu, but am yet to use it. it is expecting to see a knock sensor (got the sensor, but haven't got a good look at the rest of the set up and control system that goes with it yet) and an over boost pressure switch (which could be dummy loaded to simulate it). when I tried it out it fault coded its arse off and refused to fire all cylinders. I need to look into this further, sounds like a summer project.
the existing mpfi ecu worked fine, although I am suspect on its fuel and ignition mapping so I have been fairly gentle on it, and kept the boost std in fear of blowing it.
ensure it is a 4 plug ecu, and it should work fine.
make sure your O2 sensor is working fine, and it will compensate to some degree. I have a Jaycar kit attached to mine, so I can see it doing its best to keep things under control.
the wiring loom diagram shows a turbo/non turbo discriminator wire, similar to a manual/auto discriminator, which apparantly is either open or closed circuit, depending on which one it is. I tried that out, but didn't notice any change....
Replace or recore the radiator, your going to be generating more heat load..
I'm sure I am about to get picked apart by others who have done it properly, get in touch with steve_rising_sun, he seems to have done just about everything you can think of to early subs.
good luck finding an engine though, before I spoke with steve, I could find only one in adelaide, for a price that made an EJ worth a look.