I would go A frame off the disabled vehicle recovery points but if you go single bar maybe 2 inch square section.
Drill one end for a Reese Pin and weld a plate on the other for a Trailer Hitch attachment point
I would go for a hitch that has a Universal Joint style like McHitch or whomever
Using a single bar the disabled vehicle will need a damn solid attachment point in the centreline
Not many people have a Hitch Receiver on their front bar.
I happen have that on mine as it is where my Winch and Cradle attach if I am winching from the front or a tongue and tow ball for pushing my Van around (my winch and cradle are normally attached to a 2 inch receiver on the back cross member of the chassis)