Agreed. Marine carburetors, distributors, starters, and alternators are built in a manner to reduce errant sparks in an enclosed boat bilge.
Automotive components do not have that feature. A few ounces of vaporized gasoline in an enclosed marine engine compartment lays the groundwork for a...
I can't pick what is best for you. If I had a billfold full of excess cash, I'd like a Toyota 1HD-FTE. But I would certainly not kid myself that I'd get back the money spent doing it for the fuel economy improvement gained. .
Toyota's naturally-aspirated diesels do not take too well to turbos unless they are low-pressure units. When pushed they tend to overheat.
My opinion, of course. I'm sure there are those that will disagree.