It's a solid engine, the whole drivetrain really. Make sure you keep your splines lubed, though. obviously you'll do a full spline lube before you go, you'll probably only have to do the rear splines along the way, with the newer (post 89 I think) transmissions, they have a hardened input shaft which is good for 40-50k miles between lubes. And longer if all those miles are in a short period of time.
Don't do megasquirt. It won't really help you, the L-Jet is really reliable. My purpose of doing that is to have something to tinker with, though thus far it's been very reliable, and hasn't left me stranded in the 5000 miles or so I've used it for. If you're interested in how L-Jet works,
http://demo.cs.brandeis.edu/postscript.dump/Ltronic/Injection.htmlThe altitude comp loop is just a wire. You can add a dash switch that goes into it. Altitude compensation with fuel injection is much different than with carbs, and is much less of an issue. The plug is theoretically for over 5000 feet. I think it leans the engine slightly. I've had my K75 with the stock injection system to 14,000 feet (Mt. Evans, CO), it did fine, though it was obviously down on power: 14,000 feet is about half of the available air. I had to run it with the "Choke" lever (not really a choke, just a fast idle cam) near the second click to keep the RPM at 1100, the first click didn't have enough throttle to keep it idling. If you were doing an extended trip to those altitudes, you would just have to adjust the idle speed screw.
As to the fuel system, all you need is a standard high pressure fuel pump going to one end of the fuel rail, A hose to the Fuel pressure regulator from the other end of the fuel rail, and a return line going from the fuel pressure regulator. The fuel pressure regulator can be replaced with a more standard unit if need be: it is just a 35psi, manifold pressure compensated one.