Transformer orientation and spacing

For a while I've been collecting parts to do a build.
Have dynakit Power, transcender output, VTA octal driver and for power supply I can do component, quad or the board.
Tubes I have available are GL KT88, 6N8S, GZ37 and 5AR4 rectifier tubes.
Figured I have enough to get started laying things out.
When I first started I orientated the transformers 90 Degree to each other.  Then I remembered about some chokes I had in a drawer.
I like the way it looks with all 3 transformers but can't help to feel it's just not right.  Not sure of orientation, but really concerned about spacing.
Can I get someone to set me straight and give some recommendations?
Thanks

I would orientate the transformers as shown in your pictures.  I built a guitar amp that did have the PT and OT 90 degrees but the center lines of the xfrmers weren't lined up. As a result I had 60 cycle hum in the speaker as soon as the PT was switched on irregardless of the B+ standby switch.  It was a bear to figure out that the PT heater winding radiation was coupled directly to the OT.  Solution was to remove OT and relocate it 1/4" further away and inline with the center of the PT.

Pretty tight ... maybe downsize the OT's and save those monsters for another project.

* I suppose changing the orientation to put the iron on the long side is out of the question?

"I suppose changing the orientation to put the iron on the long side is out of the question?" {sKiZo}

My first thought exactly.

Looks can be deceiving,
Actually 12.5" wide 12" Deep

Probably best to leave the large size choke off the top and use the C-354 CHOKE underneath.

yes, I think your last though is correct "Probably best to leave the large size choke off the top and use the C-354 CHOKE underneath."
Then spread the transformers farther apart and keep them oriented as is (90 degrees from each other)