The late model 5.4's are perfectly fine, as long as sufficient viscosity is used and oil is changed regularly. Ignore the spec and use 5W-40 or 10W-40 and change it regularly. There are now a great many examples of well maintained 5.4 3V engines with North of 300,000 miles. Few to none of them got there on 5W-20 though.
I find nearly new Ford alternators on Ebay from time to time. They are removed for vehicle conversions that need more power, such as ambulance and utility trucks.