I don't know of anyone making a free wheeling hub setup ( locking hubs) for the FJ or any Toyota IFS at this point. It is an interest of mine as well. Solid Axle Industries makes the Spyntec hub conversion kit for jeeps and other vehicles, perhaps with enough interest they may take a shot at the Toyota IFS front end.
I could adapt my front bumper rather easy to accept a tow bar. Check out front bumpers at
Home Page
Stan