Whew!
I was sure hoping you got the 7.3
You did very well with your research.
The early 6.0's in 03' and 04' were very problematic.
The only common problem with the 7.3 is the cam position sensor.
Its a $110.00+/ sensor in the front of the block above the flywheel that craps out with no warning and the motor becomes a no-go. Don't buy it from Ford.
Mine went at 52,000. Luckily, I was on Pestletown Road a half mile from home. I coasted into the cemetary and left it for the night. (No one said a word.)
Buy one as soon as you can and keep it in the glove box along with a 10mm socket, a 2" extension and a thin bladed screwdriver.
You can change it roadside in about 15 minutes.
You will find Walmart to be your best bet for Shell Rotella 15w40 oil and they carry the Motorcraft Model 1995 oil filter for $9.95.
From what everyone has told me, you can look forward to about 325,000 miles out of the 7.3.
God Bless Rudolph Diesel and International!