You have to options for your diagnostics.
The easier way is to get a modern crate motor with modern electronics & computer. You can interface with it from a PC via an OBD connector. considering your budget, this shouldn't be an issue. There are other benefits to a modern FI crate motor such as fuel economy, reliable starting, and so on.
The other way would be to implement your own sensors in the engine and cobble together an interface. You'd be tapping places to mount sensors in the proper locations (engine block, intake manifold, headers, etc.). It would be the cheaper route, but you've got to know what you're doing 100% as far as reading data from the sensors and outputting the data.
Honestly, the first option is going to be the better, more reliable option. I don't know if a full-on crate motor is in your budget. You might be able to find a used motor with all the modern electronics from a junker vehicle and get it running.
You could also go with an aftermarket FI system that you can tune via computer. I know that Street & Performance offers kits to pull this off, including the computer to control it all (I don't mean the PC). I have no experience with these units, but it may be another route.
Good luck and keep us apprised of your progress.
Broncos rock, and I don't mean the football team!
