alright, that clears things up for me some.. thanks guys.
Been doing alot of research and the conclusion I've come to so far is this:
The V10; great power, horrible mileage; possible spark plug blowage;
The 5.4; reliable, long lasting motor, comparable to my 351 that I have now, but not really enough power to sport in a Super Duty.. though I am tempted to go with this motor.
The 7.3 Turbo Diesel; - reliable, lots of power, long lasting, better mileage; higher maintenance costs, did I say power?