Bob,
Well here goes. I may buck my input voltage down a little, I'll be running about 500 VDC on the plates of KT66s, 460 on the screens. I've got a UL tranny but because Scott recommends pretty strongly against UL for guitar amps I'll be using a regular screen supply. Using Glasman's (I think) modeling software. Somebody's anyway.
With regards the CF question, the comment occurs later in the sited document under the heading High Power, and goes as follows.
High Power Ouput:
Where more power is needed it is preferable
to use a larger tube that is known to be more
suited for ultra-linear circuitry, such as
the KT88, KT90 or 813.
Another useful option is to run multiple
pairs of tubes in parallel push-pull, such as
the arrangement used in the GEC 400W KT88
Amplifier. It goes without saying that normal
precautions against instability and parasitic
oscillations are essential in layout, lead
dress, use of grid stopper resistors wired
directly to the pins, and keeping inputs away
from outputs. The output transformer must be
of high quality with low leakage capacitance
and low leakage inductance between windings.
Tubes should be mounted close together to
minimise inter-connecting lead length. Grid
#1 circuit resistance must be held within the
manufacturer's ratings.
A low-impedance
driver, such as a cathode-follower or
transformer is recommended.
Then here are the relevant schemes for buck/boost transformer hookup
http://tinypic.com/20fwz1d.jpg
http://tinypic.com/20fx1df.jpg
http://tinypic.com/20fx3tl.jpg
If these are too small to read, send me a PM with e-mail addy and I'll send them to you full size.
Cheers
Dan