I have the PRXB Pacbrake on my dodge. You will love it. Leave it on all the time and never replace service brakes again.I have a Pacbrake for mine. I will try to find room for it once I install my stiffer valve springs. Should be interesting when it's completed.
I never had this whole debate coming from a 3FE 80. It was 9mpg then to 18mpg now.
If I had to do a swap again I would look hard at a LS and avoid the bugs that come with a never done before type of engine swap. Big gas engines are sweet but they are everywhere just like jeeps. Not unique at all. A turbo'd 1FZ is a cool factor like a Land Cruiser.
Never go diesel for just the fuel savings.