If I were looking at the older VW bugs for a toad, I would look for a 1969 thru 1973 standard models,(not the super beetle). These models have the independent rear suspension system rather than the earlier swing axle system in the rear, and employ a twin beam torsion bar suspension with trailing arms on the front end. Also these models have four lug narrow spaced wheels rather than the earlier wide spaced star shaped large center hole wheels.
The above mentioned models also are powered by the 1600 cc engine with dual inlet port cylinder heads, and utilize 12 volt electrical systems.
Nothing has to be done structuraly in order to tow them. Tow bars as mentioned, are inexpensive, and electrical lighting hookup is pretty standard. Just put it in neutral and go.
I have owned several over the years, and have towed many of them for lots of miles. I also, in my other life was a certified VW mechanic.
About the only drawback I personally would have with having a bug as a towed, is the lack of a suitable air conditing unit for them, (I like a little comfort in my old age).