I am certainly no expert but I recommend that you find a late 80's crown vic or marquis . Most of these cars had an AOD and the trannies went out because the overdrive linkage was notorious for falling off and it was too expensive to fix an AOD. This makes them very plentiful and you see them everywhere . They are a speed density motor so modifications to the internal drive line are limited but acceptable . You only need the computer, relays, upper and lower intake and sensors, fuel rail, injectors, gas pedal with cable ... I think you get the idea .
It doesn't sound like you are trying to do anything but make your bronco run with fuel injection and it will work very well for you with this set up. If you have a vacuum booster for your brakes, you can still run the crown vic/ marquis upper, there is room. However , if you want to turn the upper around and run it towards the passenger side, you will need to get a mustang fuel rail.
Good luck ! I'm sure you will get all the help you need from the great folks on Classic...
howiebilt