Boards are easy for the EBY amp. FARCircuits has them.
Its a good design and allwos for getting good performance at higher frequencies.
Mine with a little effort does 37W on 10M (1.8W drive) and with the same drive at
40M about 55W. 80 and 20 are about 50. Never though to try 15 or 17m but
I'd expect about 44w. The 1.8W is because I use an attenuator at the amp input
as most of my HB radios do 4W which is excessive power or the amp.
FYI I run it at 28V.
It is a good amp mine is now 13 years old and still running the same set of IRF510s.
I did use a large heatsink (4x8" with 1" fins and the base thickness was .300").
Some call it overkill but no fan with a brick on the key for 10 minutes is easy.
At least one of the "70W DIY AMP" I've seen did do that power for about 1 minute
into a dummy load before it blew up. Likely self oscillation or overheat the
supplied heatsink was maybe pentium II vintage with mounting points for
a fan and not at all large or highly finned.