Tom,
I like your approach and will consider it for the 75 meter final.
The 160 rig is built so I will just add another stage of predriver
to drive the second driver stage/final. The parts I'm using run warm above 3 MHz, I have just enough room on the driver heat sink to add
a 4 FET push pull stage between both driver stages. I have some MIL
4423s that may work better. I think there are 1 amp parts in there now.
fc