Do a search here, many people have asked similar questions. I will try to answer some of them briefly to give you a basis on which to search.
Yes, the 7.3 is probably the best Ford engine ever made (actually made by International) and maybe the all time most reliable.
Maintenance is similar, fluids still get changed, parts wear out, etc. However, oil changes can run $100 or so due to the 15qts required.
Look for a truck that has been well taken care of. Maintenance records are nice, but go by the overall feel. Take it to a qualified mechanic to have it inspected.
Replacing injectors is not out of the ordinary, but expensive. 183k is somewhat early but stuff happens. I'd be more worried that only 2 were replaced. Likely the others aren't far behind and there is a lot of labor required to change them. Read up on Wikipedia about diesel engines, that will explain what injectors do.
Wobble can be caused by balance issues with the tires, poor alignment, or worn front end parts. Jack up each front tire and give it a good hard shake in every direction. There should be no movement. This is likely not a huge issue, but may require some money to fix (and is a big safety issue).
Most of these trucks will have a brake controller installed at some point in their lives. This device will activate brakes on a trailer, when attached, and does not affect the trucks brakes in any way.
The pulsing is likely warped rotors, though can have many factors. Have your mechanic inspect the brakes. Learn to change your own brakes, it is an easy job and will save you tons of money. Plus you will feel good knowing it was done right.
In general, avoid the 2001 model year unless the transmission has been replaced. All will need a transmission job at some point but the 2001s are more prone due to a change in a "mechanical diode". Look that up for more info. Any year is fine other than that. The connecting rods changed from forged to Powdered Metal (PMRs) in 2001 which are weaker, but hold up no problem under normal use (up to 400HP or so).
There was a new interior in 2001 and a new gauge cluster in 2002 but all years are pretty similar otherwise. Early 99 trucks have some other changes so I would just avoid that year for a buyer like you.
Any other questions, feel free to ask (after you search