To me the5.0 would probably win out because of the sound of the engine, the whine, and you can have any amount of power your pocket can handle. It is by far the simplest install of any motor out there, even if the motor has its own stand alone harness/computer. A new harness or one from an earlier Stang would give you a three wire hookup, again simple.
The new power stroke, something to consider but I would think almost everything would have to fabricated, harnessing could be interesting but since you have an '88, might not be too bad.
Something to look into, cost vs result vs time.
Luck with it.
You've got me thinking 5.0 AGAIN !