I am a little confused. You are willing to install a whole different motor, and you have replaced the fuel filter and IT GOT BETTER and you have yet to get a fuel pressure reading, at idle and while driving. A clogged fuel filter likely over worked the fuel pump and when you changed the filter, that pump breathed for a while and then the problem popped up again. 10 motors later, you still have the same old fuel delivery. I would rather drop a tank and install a fuel pump than swap out a motor, unless of course the motor is actually needed.
C'mon man. Get the fuel pressure readings and post here. That fuel pump change dread is because of the rust, right?
By the way, welcome to the forum from Oregon. By the way, move from Maryland to Utah was smart.