AAA SUX!!!!
I bought a car dolly (and a winch) and have 2 vehicles that can pull it.
I basically own my own tow truck.
One of the best investments I've ever made.
Did I read right that the OP already owns a tow truck, but has a sling?
My advice would be- get a dolly for that truck to pull and stop depending on others. You know what "they" say- "if you want something done right....."