An other Aleph.....the Aleph 1.2

I would certainly not biuld an Aleph 1.2 for myself.But I talked about the unique sounding of the Aleph series to a friend,but for the studio he wants 200 W.
I told him:possible!I can build those mono-blocks for you...No problem.
The design will mostly look like Nelson's.In fact I have no other choice....the amp's chassis will be a huge square heatsink totalizing 340X340X250,I plan to use a 1 m bar cutted into 4 parts.
As I will have to dissipate 500W,dispached on 4 heatsinks means 125W per piece.With 0,25deg/W four times it means 31,25 deg above ambiant,for a typical tamp.of 57 degrees celsius.

I am wondering for power supply I should get 64V before filtering/chokes,shall I use 2X toroid 24V 500VA ,with 2 secondaries split in series?????
What value for bank capacitors shall I take??.

Do you know a better place than DIGIKEY to order the IRFP240 ( I mean cheaper,but still from I.R.?????)
Thanks for help!!!!!!!!