Our Infinity would be the perfect first mod for you. It is a programmer/monitor that will hold an unlimited amount of tunes, monitor generic and Ford enhanced PID's, read/clear codes, datalog, run tests(KOEO/KOER, buzz, cylinder contribution, glow plug), play media, and much more.
Once you have the Infinity, there is no need for any other diagnostic equipment or programmers.
You can check it out HERE
The next mods after that would be a coolant filter and exhaust in my opinion.
Let me know if you have any questions about the Infinity. I would be glad to help you out.