Rudolph Harbig. If you don't know his story check it out. His 800m WR is one of the greatest WR's ever given the era, performance and circumstances.
And this might seem a bit out of left field, but a movie about the Robertson twins from NZ - depending on how accurate they want to make it, would be riveting and wild.
These weren't two kids who went to Kenya to join some structured training camp under a management group. They literally packed bags and left home to move to Kenya with no contacts, no idea what or how they were going to do anything, arrived in Nairobi and basically just bootstrapped the whole thing.
One ended up in Ethiopia, the other sleeping on the floor in Stephen Cheronos (Saif Shaaeed Shaheens) garage. Running from guys with machetes, sticking dish soap up tight places to avoid doping control, all the while have intricate knowledge of everything that goes down in that country with respect to the world of "professional" athletics.
That movie would top anything. Seriously.