OK. I have done more research. I now know that the more I learn about injectors, the more there I to learn!
EV14 injectors seem to be the best kind available right now but I might have to buy adapters and there aren't many that are available under 550cc/min. I am concerned that injectors of this flow rate may be difficult to tune...
So, the best compromise I think is these EV6 ones:http://www.ebay.com.au/itm/291138455938
Not Bosch original but appear OK. Shame they have to come from Australia! It's actually possible to buy injectors from China or Hong Kong for about £60 for a set, but I think I am well advised to steer clear of such things, especially with something as critical as injectors! Though I always wonder if they are as bad as all that. I also wonder how they get away with continuing to sell them if they are indeed terrible!
Anyway, I digress. I now realise that my aim of allowing easy swap back to the OE ECU and loom isn't likely to be realised. There are just too many wires to join and the loom is too intertwined with everything else to be easily reinstated.
Now an update on actual progress: I have carefully removed the OE engine wiring from the loom. I have removed every single wire to the engine and associated sensors and controls, injectors, etc., etc. I have also removed the ECU plug. I carefully cut the wires near the base of the ECU plug. I left the wires that go to the rest of the car's loom with a few inches available so I can connect to them. I did the same with those that go to the relay board.
I didn't cut out the wires that go to the alternator, AC compressor and engine bay fans. My reasoning was that they don't carry signals for sensors and they all looked in good condition.
I labelled all loose ends with DYMO labels so that I know where to connect to when I build in the new wiring.
Oh and it seems I now have a deadline for the work!! My fiancee has suggested we use the car for our honeymoon in September! I think it will be tough to get it finished, mapped and reliable ahead of that but we shall see