A guide to building the Pass F4 amplifier

Hello, how you guys doing?

I had to dismantle my stereo setup and left all as it is, the BA3 and F4 working but somehow feeling not complete. With enough time to think about it the idea is to make the BA3 balanced (there already is a second PSU), I got a board and will only need to populate it and then add balanced outputs.

On the other hand my doubt is about how to make mono-bridge the F4 and make it balanced so that I can then have another one done and pull out 50W each.

My F4 was built dual mono so it has two transformers, if I recall correct 230VA each, if the project sees the light I'd want both F4 to be exactly the same, what is your suggestion, provided it is feasible, make the second F4 as the first, in dual mono fashion with twin transformers or swap the two for one and make things easier (but more expensive by swapping)?

Thank you