Hi Giora.
Have you already considered a single switch forward for your design?
Push-pull topology is much more suitable for high currents, with only 80W output power I don't think you are in that condition...
And more: output current is very low, so your output inductance will be very low and very small, since you can tolerate that output voltage ripple.
You can try to evaluate this solution with the Power Design Tool available on the TI website.
Bye
Paolo