If you havent already, try spraying some non-chlorinated brakecleen or ether into the throttle body and see if it fires. That will tell you which end isnt working, fuel or fire.
If it fires, then check the injector clips and see if they pulse while cranking, typically the ECU controls injector ground while they will get 12v full time with key. (So yes, most likely the ECU needs to be bolted in while trying a different unit)
If it doesnt fire, you can still check the above to make sure that end is working, and move on to either bad coil, or pickup in the distributor (ignoring possibly ecu and grounds)