Help about transformer for PWM Power Supply

Hello there,
I'm start building an audio amplifier about 2x120w RMS @ 8ohms and 4 or 8ohms stable Class AB.
Output devices are 2*2SA1943 / 2*2SC5200 each channel.
I want running this about +/-60vDC, so for 4ohms usage is need too many amperage.
To use standard transformer is too expensive and too heavy.
The amp is intended for mobile DJ usage so i want to keep it light and DONT heavy.

I have circuit for classic half bridge TL494 for drive and lots of high voltage / amperage FETs from old computer PSUs.
But i'm confused about transformer. i have lots of ferrite cores and classic "EI" from computer PSUs to change the primary / secondary windings. Also i have insulated wire about 0.6, 0.8, 1, 1.2mm thickness.
So what is the calculation for one primary winding or two primary windings to get the result for 2 secondary windings to take 2x60vDC rectified?
For car audio transformers i use the calculator from here:
Basic Switching Power Supply Design Tutorial
and i'm changing the running voltage for my car amps with totally success.
But the main voltage now is >300vDC and i'm affraid to make experiments :D

I like the opinion from this community because something you know more than me.
Regards.