UCC28C53: Recommendations for a Flyback Design Challenge

We are in need of an Isolated Flyback DC/DC Converter design to work with a 24 to 96V battery system. It is to be a 15-140V input to 12V output voltage and, 4-5A nominal 9A peak output current converter. We want to use the Würth transformer "749196547", for its ease on customization. Such as the option of paralleling all the secondary windings in order to reach the output current requirements. 

 

We would appreciate any suggestions to help us best solve this design challenge. Such as the choice in using either a high voltage supply PWM controller or using one of the primary windings as auxiliary supply for the PWM controller like a UCC28C53. Notably, we tried finding a suitable design at Webench, but it proved hard since we do not want to use a custom transformer.

 

The design could be made in a two-stage structure with the voltage range divided in two, if it turns out to be much more convenient that way. But our first choice is that it is done in one stage.